Some stats on clang vs gcc by running supersize on a local build with GCC vs Clang:

Per-Section Summary:

Section Sizes (Total=-280kb (-287355 bytes)):
    .bss: 10.2kb (10496 bytes) (not included in totals)
    .data: -52.6kb (-53912 bytes) (18.8%)
    .data.rel.ro: 816kb (835584 bytes) (-290.8%)
    .data.rel.ro.local: -806kb (-825344 bytes) (287.2%)
    .rel.dyn: 14.6kb (14944 bytes) (-5.2%)
    .rodata: -53.6kb (-54856 bytes) (19.1%)
    .text: -205kb (-210236 bytes) (73.2%)
    .init_array: -180 bytes (-180 bytes)

* Interesting that there is 50kb smaller .rodata and .data.
* Looks like ".data.rel.ro.local" is renamed to ".data.rel.ro"
* .init_array is smaller. Likely there are now fewer files with static initializers (yay!).
  * This makes sense since our bots were only blocking SI additions on platforms that use clang.
  * Print(diff.symbols.WhereNameMatches(r'^_GLOBAL__')) shows there are 54 fewer static initializers.


132596 symbols added (+), 271039 changed (~), 29028 removed (-), 81536 unchanged (not shown)
Number of unique symbols 324513 -> 376006 (+51493)
1 paths added, 14 removed, 15044 changed

* ~100k new symbols, of which ~51k are not just aliases. That's quite a bit!
  * Probably this is a result of less inlining.

Let's look at coverage:
GCC has:
Section r: has 100.0% of 6242382 bytes accounted for from 21210 symbols. 0 bytes are unaccounted for.
* Padding accounts for 1724 bytes (0.0%)
* 10 placeholders (symbols that start with **) account for 2884482 bytes (46.2%)
* 916 symbols have shared ownership (264762 bytes)
Section b: has 100.0% of 1940827 bytes accounted for from 19969 symbols. 77 bytes are unaccounted for.
* Padding accounts for 1061 bytes (0.1%)
* 0 symbols have shared ownership
Section d: has 100.0% of 1998112 bytes accounted for from 27882 symbols. 0 bytes are unaccounted for.
* Padding accounts for 2139 bytes (0.1%)
* 1272 symbols have shared ownership (55872 bytes)
Section t: has 100.0% of 37699764 bytes accounted for from 334044 symbols. 0 bytes are unaccounted for.
* Padding accounts for 46271 bytes (0.1%)
* 10 placeholders (symbols that start with **) account for 357269 bytes (0.9%)
* Contains 88157 aliases, mapped to 9565 unique addresses (568598 bytes)
* 18185 symbols have shared ownership (1008722 bytes)


Clang has:
Section r: has 100.0% of 6187526 bytes accounted for from 15685 symbols. 0 bytes are unaccounted for.
* Padding accounts for 6677 bytes (0.1%)
* 23 placeholders (symbols that start with **) account for 2967019 bytes (48.0%)
* 500 symbols have shared ownership (259420 bytes)
Section b: has 100.0% of 1951307 bytes accounted for from 12627 symbols. 93 bytes are unaccounted for.
* Padding accounts for 4634 bytes (0.2%)
* 0 symbols have shared ownership
Section d: has 100.0% of 1954440 bytes accounted for from 27764 symbols. 0 bytes are unaccounted for.
* Padding accounts for 4945 bytes (0.3%)
* 1076 symbols have shared ownership (44975 bytes)
Section t: has 100.0% of 37489528 bytes accounted for from 442143 symbols. 0 bytes are unaccounted for.
* Padding accounts for 70165 bytes (0.2%)
* 9 placeholders (symbols that start with **) account for 542105 bytes (1.4%)
* Contains 136107 aliases, mapped to 13889 unique addresses (589382 bytes)
* 38218 symbols have shared ownership (1375282 bytes)

* clang has fewer .rodata symbols, yet more bytes lost to alignment
* clang has more bytes attribute to "** merge strings"
* clang has ~50% fewer .rodata symbols that show up in the nm output of .o files.
* clang has even more space attributed to symbol gaps in .text ( bug 709050 )



Let's look at .o files that are added/removed:

Added files:
  third_party/android_tools/ndk/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a/libc++abi.a/cxa_aux_runtime.o
Removed files:
  cc/ipc/compositor_frame_metadata.mojom.cc
  cc/ipc/filter_operations.mojom.cc
  components/tracing/proto/event.pbzero.cc
  components/tracing/proto/events_chunk.pbzero.cc
  services/ui/public/interfaces/window_tree.mojom.cc
  third_party/android_tools/ndk/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/lib/gcc/arm-linux-androideabi/4.9.x/libgcc.a/_ctzdi2.o
  third_party/android_tools/ndk/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/lib/gcc/arm-linux-androideabi/4.9.x/libgcc.a/_popcountdi2.o
  third_party/android_tools/ndk/toolchains/arm-linux-androideabi-4.9/prebuilt/linux-x86_64/lib/gcc/arm-linux-androideabi/4.9.x/libgcc.a/_popcountsi2.o
  third_party/protobuf/src/google/protobuf/stubs/structurally_valid.cc
  third_party/skia/src/core/SkDeviceProfile.cpp
  third_party/skia/src/core/SkExecutor.cpp
  third_party/skia/src/core/SkLiteDL.cpp
  ui/base/cursor/cursor_data.cc
  v8/src/trap-handler/handler-shared.cc


* I don't think the linker does any inlining across .o files, so I think the removed files would be due to symbols in those files now being unreferenced (as opposed to them just being entirely inlined).
* Digging into a few of these paths:

>>> Print(diff.symbols.WherePathMatches(r'cxa_aux_runtime'))
+ 0)         40 (100.0%) t@0x266a078  40      third_party/android_tools/ndk/sources/cxx-stl/llvm-libc++/libs/armeabi-v7a/libc++abi.a/cxa_aux_runtime.o
               __cxa_bad_typeid

>>> Print(diff.symbols.WherePathMatches(r'compositor_frame_metadata.mojom.cc'))
- 0)         -8 (100.0%) r@0x0        -8      cc/ipc/compositor_frame_metadata.mojom.cc
               CSWTCH.95

>>> Print(diff.symbols.WherePathMatches(r'components/tracing/proto/event.pbzero.cc'))
- 0)       -160 (100.0%) t@0x0        -160    components/tracing/proto/event.pbzero.cc
               _GLOBAL__sub_I_event.pbzero.cc
- 1)       -160 (100.0%) b@0x0        -96     components/tracing/proto/event.pbzero.cc
               pbzero::tracing::proto::kFields_Event
- 2)       -160 (100.0%) b@0x0        -16     components/tracing/proto/event.pbzero.cc
               kInvalidField

* The 2nd one leads me to believe that gcc/gold was not properly removing unused generated symbols for switch statements.
* The 3rd one corroborates .init_array being smaller. The _GLOBAL is a static-initializer, which likely causes the other symbols to be kept.


Let's look at the largest changed symbols:

Index, Running Total, Section@Address, PSS
------------------------------------------------------------
~ 0)     184836 (-59.9%) t@Group      184836  {no path}
               ** symbol gaps (count=10)
~ 1)     301239 (-97.6%) t@0x485a60   107256  third_party/skia/src/core/SkColorSpaceXform.cpp
               SkColorSpaceXform_XYZ::onApply const
~ 2)     386131 (-125.1%) t@0x4a09f0   84892   third_party/skia/src/core/SkColorSpaceXform.cpp
               SkColorSpaceXform_XYZ::onApply const
~ 3)     470339 (-152.3%) t@0x4b6070   84208   third_party/skia/src/core/SkColorSpaceXform.cpp
               SkColorSpaceXform_XYZ::onApply const
~ 4)     546998 (-177.2%) r@Group      76659   {no path}
               ** merge strings (count=7)
+ 5)     576586 (-186.7%) t@0x2e6980   29588   chrome/browser/about_flags.cc
               startup
~ 6)     598850 (-194.0%) t@0x535f20   22264   third_party/skia/src/core/SkScan_AAAPath.cpp
               SkScan::AAAFillPath
+ 7)     619330 (-200.6%) t@0x156caf8  20480   third_party/libjpeg_turbo/jchuff.c
               encode_one_block
~ 8)     639454 (-207.1%) t@0x1035800  20124   v8/src/compiler/typer.cc
               v8::internal::compiler::Typer::Visitor::Reduce
~ 9)     658122 (-213.1%) t@0x5b1c34   18668   third_party/skia/src/effects/SkLightingImageFilter.cpp
               SkDiffuseLightingImageFilter::onFilterImage const
...

* Most of these are probably the result of different inlining decisions.
* As above, would love to know what these gaps are all about ( bug 709050 )
* Might be more useful to look on a per-file basis to avoid inlining differences.

>>> Print(diff.symbols.GroupedByPath().Sorted())

Index, Running Total, Section@Address, PSS
------------------------------------------------------------
~ 0)     279926 (-90.7%) *@Group      279926  {no path} (count=9)
~ 1)     394433 (-127.7%) *@Group      114507  third_party/skia/src/core/SkColorSpaceXform.cpp (count=148)
~ 2)     439141 (-142.2%) *@Group      44708   v8/src/crankshaft/hydrogen.cc (count=574)
~ 3)     403683 (-130.7%) *@Group      -35458  third_party/libyuv/source/row_common.cc (count=48)
~ 4)     370555 (-120.0%) *@Group      -33128  v8/src/parsing/parameter-initializer-rewriter.cc (count=40)
~ 5)     341288 (-110.5%) *@Group      -29267  content/common/content_message_generator.cc (count=5227)
~ 6)     370180 (-119.9%) *@Group      28891   third_party/skia/src/effects/SkLightingImageFilter.cpp (count=159)
~ 7)     397393 (-128.7%) *@Group      27213   third_party/skia/src/core/SkLinearBitmapPipeline.cpp (count=382)
~ 8)     424492 (-137.5%) *@Group      27099   third_party/harfbuzz-ng/src/hb-ot-layout.cc (count=668)
~ 9)     451418 (-146.2%) *@Group      26925   v8/src/bootstrapper.cc (count=105)
~ 10)    478006 (-154.8%) *@Group      26588   third_party/sqlite/amalgamation/sqlite3.c (count=1802)
~ 11)    504557 (-163.4%) *@Group      26551   third_party/libwebp/dsp/{shared} (count=58)
~ 12)    531025 (-172.0%) *@Group      26468   v8/src/inspector/protocol/Runtime.cpp (count=174)
~ 13)    554935 (-179.7%) *@Group      23909   v8/src/objects.cc (count=902)
~ 14)    577375 (-187.0%) *@Group      22439   v8/src/runtime/runtime-debug.cc (count=211)
~ 15)    598515 (-193.8%) *@Group      21140   base/third_party/dmg_fp/dtoa_wrapper.cc (count=32)
~ 16)    618603 (-200.3%) *@Group      20087   v8/src/compiler/typer.cc (count=102)
~ 17)    637277 (-206.4%) *@Group      18673   third_party/libwebp/dsp/yuv.c (count=30)
~ 18)    618839 (-200.4%) *@Group      -18438  v8/src/compiler/simplified-lowering.cc (count=91)
~ 19)    600768 (-194.6%) *@Group      -18070  v8/src/ast/ast-numbering.cc (count=53)
~ 20)    618052 (-200.2%) *@Group      17284   v8/src/runtime/runtime-atomics.cc (count=30)
~ 21)    635285 (-205.8%) *@Group      17232   v8/src/inspector/protocol/Debugger.cpp (count=119)
~ 22)    650979 (-210.8%) *@Group      15693   v8/src/parsing/parser.cc (count=232)
~ 23)    635647 (-205.9%) *@Group      -15332  third_party/libyuv/source/scale_common.cc (count=20)
~ 24)    650071 (-210.5%) *@Group      14424   v8/src/deoptimizer.cc (count=133)
~ 25)    664261 (-215.1%) *@Group      14190   chrome/browser/about_flags.cc (count=119)
~ 26)    650391 (-210.6%) *@Group      -13869  v8/src/compiler/ast-loop-assignment-analyzer.cc (count=50)
~ 27)    663387 (-214.9%) *@Group      12995   gpu/command_buffer/service/gles2_cmd_decoder_passthrough_doers.cc (count=362)
~ 28)    650643 (-210.7%) *@Group      -12743  gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc (count=487)
~ 29)    663065 (-214.7%) *@Group      12421   {shared} (count=12215)
~ 30)    675254 (-218.7%) *@Group      12189   v8/src/wasm/wasm-objects.cc (count=100)
~ 30)    675254 (-218.7%) *@Group      12189   v8/src/wasm/wasm-objects.cc (count=100)
~ 31)    663916 (-215.0%) *@Group      -11338  ui/gl/gl_bindings_autogen_gl.cc (count=1586)
~ 32)    652648 (-211.4%) *@Group      -11268  v8/src/interpreter/bytecode-decoder.cc (count=7)
~ 33)    663874 (-215.0%) *@Group      11226   v8/src/runtime/runtime-regexp.cc (count=114)
~ 34)    675078 (-218.6%) *@Group      11203   content/{shared} (count=1161)

* Index 0 is the symbol gaps thing again.
* SkColorSpaceXform has come up a couple times for its size (bug 660416,  bug 677450 ). It seems clang makes it even bigger.
* The diff here can't be 100% trusted, since there may be different sharing of symbols going on.
  * When a symbol is listed in the nm output of multiple .o files, its path is set to common_anscestor/{shared}
* Still, the sharing information should be somewhat consistent between GCC & clang, so I think there a good chance that GCC produces smaller code for most of these that are marked as increases.
* clang is only smaller because it has a long tail of files that shrink by < 1kb

Other interesting queries:

>>> Print(canned_queries.CategorizeGenerated(diff.symbols))
Showing 8 symbols (8 unique) with total pss: 385423 bytes
.text=378kb      .rodata=-580 bytes .data*=-1386 bytes .bss=-672 bytes total=376kb
Number of unique paths: 1551

Index, Running Total, Section@Address, PSS
------------------------------------------------------------
0)     228623 (59.3%) *@Group      228623  Mojo (count=9077)
1)     313657 (81.4%) *@Group      85033   Protocol Buffers (count=4780)
2)     357055 (92.6%) *@Group      43398   Blink (bindings) (count=3854)
3)     375423 (97.4%) *@Group      18368   DevTools (count=739)
4)     387100 (100.4%) *@Group      11677   Blink (IDL) (count=637)
5)     387032 (100.4%) *@Group      -68     RegisterJNI (count=4)
6)     383422 (99.5%) *@Group      -3610   Blink (Other) (count=388)
7)     385423 (100.0%) *@Group      2000    Other (count=260)

>>> Print(canned_queries.CategorizeByChromeComponent(diff.symbols))
Showing 25 symbols (25 unique) with total pss: -308764 bytes
.text=-205kb     .rodata=-53.6kb    .data*=-42.6kb    .bss=10.2kb     total=-301kb
Number of unique paths: 15552

Index, Running Total, Section@Address, PSS
------------------------------------------------------------
0)     292884 (-94.9%) *@Group      292884  V8 (count=29304)
1)     443110 (-143.5%) *@Group      150226  Skia (count=12430)
2)     541304 (-175.3%) *@Group      98193   Blink (generated) (count=6244)
3)     623348 (-201.9%) *@Group      82044   Codecs (count=6016)
4)     646459 (-209.4%) *@Group      23110   ICU (count=7878)
5)     658155 (-213.2%) *@Group      11696   libxml (count=1109)
6)     664589 (-215.2%) *@Group      6433    WebBluetooth (count=3854)
7)     667454 (-216.2%) *@Group      2865    XSLT (count=450)
8)     668265 (-216.4%) *@Group      810     WebUSB (count=2564)
9)     667477 (-216.2%) *@Group      -787    Cast (count=258)
10)    666124 (-215.7%) *@Group      -1353   FileSystem (count=1555)
11)    663799 (-215.0%) *@Group      -2324   WebCrypto (count=665)
12)    660965 (-214.1%) *@Group      -2834   Printing (count=1032)
13)    657836 (-213.1%) *@Group      -3128   Media Source (count=691)
14)    654573 (-212.0%) *@Group      -3263   Internals Pages (count=1701)
15)    650557 (-210.7%) *@Group      -4015   Prefetch (count=851)
16)    645658 (-209.1%) *@Group      -4898   WebVR (count=3227)
17)    638185 (-206.7%) *@Group      -7473   Password Manager (count=2489)
18)    621084 (-201.2%) *@Group      -17101  Autofill (count=5732)
19)    595044 (-192.7%) *@Group      -26039  WebGL (count=3358)
20)    467801 (-151.5%) *@Group      -127242 WebRTC (count=22354)
21)    -61412 (19.9%) *@Group      -529214 Blink (non-generated) (count=133969)
22)    -75687 (24.5%) *@Group      -14274  Other Third-Party (count=17147)
23)    204238 (-66.1%) *@Group      279926  ** Merged Symbols (count=8)
24)   -308764 (100.0%) *@Group      -513002 Other (count=249313)

* V8, Skia, and many Codecs all increased in code size when compiling with clang.
  * These also happen to be targets that set optimize_max:
    * https://cs.chromium.org/search/?q=optimize_max+file:%5C.gn
  * Seems likely that -O2 on clang generates larger code than -O2 on gcc.
  * May be worth revisiting whether we need optimize_max for all of these.
* Blink decreased the most, by a whopping 500kb.
  * But again, due to the shared path subtlety pointed out above, these numbers should also be taken with a grain of salt, as they are mostly based on paths.

Interesting numbers! pcc might find them interesting.

I'll dupe this into the parent since we ended up switching globally instead of per-arch.

Another interesting tidbit is that the switch increases our update patch size by 20mb:

https://chromeperf.appspot.com/report?sid=0fcfa4d16fe0d04158a52a82000224676acfdadb010095337cd330f0c716ae90&num_points=4000

Obviously unavoidable, but +nyquist, +amineer as fyi

Just to be clear, that bump in patch size is a one-off across all our channels, right? I mean, for the next release after the big patch size, it'd go down to normal levels?
The charts aren't clear on that, as I assume they always goes towards the latest released one?

Out of interest: for a stable update I would expect this to be not super uncommon since quite a bit of code changes between stables. Is that correct? What's the usual diff size for stable updates? (For minor updates on stable, or between dev updates, I'd expect diff sizes to be much smaller normally.)

We update clang much more frequently than we used to update the ndk and its compiler. I wouldn't be surprised if diff size after compiler updates are fairly large too. We used the "full stable update diffs will be large-ish anyway" theory to justify that.

Re 4: In general yes, modulo the more frequent compiler updates, which I'd expect might sometimes cause larger one-time diffs too.

Attaching .size files that I looked in case anyone else (including future self) wants to do some comparisons.

Deleted: gcc-arm-MonochromePublic.apk.size 5.8 MB

gcc-arm-MonochromePublic.apk.size 5.8 MB Download

The diff varies a bit dependent on lots of different things. For arm earlier this year, I think the bsdiff updates were typically around ~15 MB (ballpark number).
Except for builds that target before Android L (in Chrome's case, that's Android J and Android K), for  which it's around ~30MB (again, ballpark).

Yeah, if this is +20MB for each upgrade (and so we move from 15MB -> 35MB as an average) I don't know that's going to be acceptable.  nyquist@, is there any way we could estimate what that would do to our up to date rate?

I don't think there's a way to predict how the compiler is going to change in the future. I also don't think that future diffs will be this large.

Let's monitor how this develops, and if it does stay that high, then let's come up with something then (a limit on how often to rev the compiler, or something).

(Also, I should point out that the compiler revision is pinned in src.git, so on a branch the compiler never changes and minor stable release diff sizes will be 100% unaffected.)

> I don't think there's a way to predict how the compiler is going to change in the future. I also don't think that future diffs will be this large.

Can we s/think/know here by performing some analysis or is that impossible?

You could try building several previous milestones with clang (I'd guess that most of them should compile fine, but we don't have offical clang bots afaik, so who knows) and compute patch diff sizes between those binaries I suppose.

Note: A recent change removed 275kb from SkColorSpaceXform.

https://skia-review.googlesource.com/c/19744/

Not sure if this is useful at all:

Top 50 .rodata diffs by path:

>>> Print(Diff().symbols.WhereInSection('r').GroupedByPath().Sorted())

141 symbols added (+), 2332 changed (~), 1439 removed (-), 421 unchanged (not shown)
Number of unique symbols 21210 -> 15686 (-5524)
140 paths added, 1414 removed, 2158 changed

Showing 4,333 symbols (aliases not grouped for diffs) with total pss: -54856 bytes
.text=0 bytes    .rodata=-53.6kb    .data*=0 bytes    .bss=0 bytes    total=-53.6kb
Number of unique paths: 4236

Index | Running Total | Section@Address | Δ PSS (Δ size_without_padding) | Path
------------------------------------------------------------
~ 0)      85254 (-155.4%) r@Group      +85254 (2884481->2966990)  {no path} (count=3)
~ 1)      81406 (-148.4%) r@Group      -3848 (118912->115064)  third_party/webrtc/modules/rtp_rtcp/source/forward_error_correction_internal.cc (count=1254)
~ 2)      84421 (-153.9%) r@Group      +3015 (104->3119)   content/browser/appcache/appcache_database.cc (count=42)
~ 3)      81739 (-149.0%) r@Group      -2682 (26504->23822)  content/common/content_message_generator.cc (count=742)
~ 4)      79241 (-144.5%) r@Group      -2498 (20363->17887)  {shared} (count=59)
+ 5)      81551 (-148.7%) r@Group      +2310 (0->2310)     components/history/core/browser/thumbnail_database.cc (count=24)
~ 6)      83805 (-152.8%) r@Group      +2254 (328->2582)   components/offline_pages/core/offline_page_metadata_store_sql.cc (count=24)
~ 7)      81627 (-148.8%) r@Group      -2178 (2216->38)    third_party/zlib/inflate.c (count=4)
+ 8)      83803 (-152.8%) r@Group      +2176 (0->2176)     third_party/zlib/{shared} (count=2)
~ 9)      81643 (-148.8%) r@Group      -2160 (38392->36232)  chrome/browser/flag_descriptions.cc (count=620)
- 10)     79627 (-145.2%) r@Group      -2016 (2016->0)     third_party/webrtc/pc/peerconnectionfactory.cc (count=59)
~ 11)     81482 (-148.5%) r@Group      +1855 (1856->3708)  third_party/WebKit/Source/core/frame/UseCounter.cpp (count=2)
~ 12)     79716 (-145.3%) r@Group      -1766 (5448->3682)  v8/src/interpreter/bytecodes.cc (count=314)
~ 13)     81327 (-148.3%) r@Group      +1611 (168->1764)   ui/events/keycodes/keyboard_code_conversion_android.cc (count=3)
~ 14)     82812 (-151.0%) r@Group      +1485 (288->1773)   components/offline_pages/core/background/request_queue_store_sql.cc (count=22)
~ 15)     84208 (-153.5%) r@Group      +1396 (144->1540)   components/history/core/browser/download_database.cc (count=5)
- 16)     82864 (-151.1%) r@Group      -1344 (1344->0)     gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc (count=1)
~ 17)     81570 (-148.7%) r@Group      -1294 (22960->21666)  third_party/{shared} (count=20)
~ 18)     82845 (-151.0%) r@Group      +1275 (500->1612)   third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp (count=76)
~ 19)     81589 (-148.7%) r@Group      -1256 (1316->57)    third_party/webrtc/pc/peerconnection.cc (count=57)
~ 20)     80397 (-146.6%) r@Group      -1192 (2552->1360)  gpu/command_buffer/service/gles2_cmd_validation.cc (count=54)
~ 21)     79266 (-144.5%) r@Group      -1131 (1152->21)    content/browser/service_worker/service_worker_storage.cc (count=43)
~ 22)     78218 (-142.6%) r@Group      -1048 (2144->1096)  third_party/libvpx/source/libvpx/vp8/encoder/vp8_quantize.c (count=6)
~ 23)     77194 (-140.7%) r@Group      -1024 (9216->8192)  third_party/usrsctp/usrsctplib/usrsctplib/netinet/sctp_crc32.c (count=9)
~ 24)     76182 (-138.9%) r@Group      -1012 (1032->20)    third_party/webrtc/pc/channel.cc (count=43)
~ 25)     75189 (-137.1%) r@Group      -993 (17824->16811)  third_party/harfbuzz-ng/src/hb-ot-shape-complex-indic.cc (count=12)
~ 26)     74275 (-135.4%) r@Group      -914 (8640->7726)   chrome/common/pref_names.cc (count=250)
~ 27)     75175 (-137.0%) r@Group      +900 (600->1500)    v8/src/wasm/wasm-opcodes.cc (count=54)
~ 28)     76061 (-138.7%) r@Group      +886 (184->1070)    components/previews/core/previews_opt_out_store_sql.cc (count=19)
~ 29)     75265 (-137.2%) r@Group      -796 (6304->5508)   content/public/common/content_switches.cc (count=229)
~ 30)     74566 (-135.9%) r@Group      -699 (720->20)      components/history/core/browser/history_service.cc (count=34)
- 31)     73870 (-134.7%) r@Group      -696 (696->0)       components/autofill/core/browser/webdata/autofill_webdata_service.cc (count=27)
~ 32)     73177 (-133.4%) r@Group      -693 (752->59)      content/browser/renderer_host/render_process_host_impl.cc (count=39)
~ 33)     72537 (-132.2%) r@Group      -640 (656->16)      third_party/webrtc/pc/{shared} (count=39)
+ 34)     73176 (-133.4%) r@Group      +639 (0->639)       components/history/core/browser/top_sites_database.cc (count=5)
- 35)     72568 (-132.3%) r@Group      -608 (608->0)       chrome/browser/android/vr_shell/vr_gl_thread.cc (count=29)
~ 36)     71975 (-131.2%) r@Group      -593 (616->23)      content/browser/background_sync/background_sync_manager.cc (count=23)
- 37)     71391 (-130.1%) r@Group      -584 (584->0)       content/browser/service_worker/service_worker_context_wrapper.cc (count=22)
~ 38)     71968 (-131.2%) r@Group      +577 (128->668)     content/renderer/accessibility/blink_ax_enum_conversion.cc (count=13)
- 39)     71432 (-130.2%) r@Group      -536 (536->0)       third_party/webrtc/p2p/base/transportcontroller.cc (count=22)
~ 40)     70901 (-129.2%) r@Group      -531 (760->229)     content/browser/service_worker/service_worker_database.cc (count=32)
~ 41)     70376 (-128.3%) r@Group      -525 (261992->261467)  net/http/transport_security_state.cc (count=81)
- 42)     69856 (-127.3%) r@Group      -520 (520->0)       components/sync/driver/glue/sync_backend_host_impl.cc (count=20)
- 43)     69344 (-126.4%) r@Group      -512 (512->0)       media/base/pipeline_impl.cc (count=29)
~ 44)     69852 (-127.3%) r@Group      +508 (96->472)      chrome/browser/android/vr_shell/ui_scene_manager.cc (count=40)
~ 45)     69354 (-126.4%) r@Group      -498 (1292->794)    gpu/config/gpu_driver_bug_list_autogen.cc (count=142)
- 46)     68859 (-125.5%) r@Group      -495 (492->0)       v8/src/{shared} (count=19)
~ 47)     69340 (-126.4%) r@Group      +481 (28280->28761)  gpu/command_buffer/service/gles2_cmd_apply_framebuffer_attachment_cmaa_intel.cc (count=5)
~ 48)     68864 (-125.5%) r@Group      -476 (5760->5284)   components/policy/policy_constants.cc (count=161)
~ 49)     68389 (-124.7%) r@Group      -475 (11926->11460)  third_party/sqlite/amalgamation/sqlite3.c (count=126)
~ 50)     67916 (-123.8%) r@Group      -473 (488->15)      content/browser/service_worker/service_worker_context_core.cc (count=17)


Top 50 .data symbols:
102 symbols added (+), 4654 changed (~), 50 removed (-), 4481 unchanged (not shown)
Number of unique symbols 27882 -> 27767 (-115)
102 paths added, 42 removed, 4480 changed

Showing 9,287 symbols (aliases not grouped for diffs) with total pss: -43672 bytes
.text=0 bytes    .rodata=0 bytes    .data*=-42.6kb    .bss=0 bytes    total=-42.6kb
Number of unique paths: 9126

Index | Running Total | Section@Address | Δ PSS (Δ size_without_padding) | Path
------------------------------------------------------------
~ 0)     -14896 (34.1%) d@Group      -14896 (17844->2948)  chrome/browser/about_flags.cc (count=98)
+ 1)     -10244 (23.5%) d@Group      +4652 (0->4648)     v8/src/interpreter/bytecode-decoder.cc (count=1)
~ 2)     -13228 (30.3%) d@Group      -2984 (23680->20696)  content/common/content_message_generator.cc (count=746)
+ 3)     -10608 (24.3%) d@Group      +2620 (0->2620)     v8/src/builtins/builtins.cc (count=1)
~ 4)      -8184 (18.7%) d@Group      +2424 (2772->5196)  ui/events/keycodes/dom/keycode_converter.cc (count=2)
~ 5)      -6416 (14.7%) d@Group      +1768 (40->1788)    net/log/net_log.cc (count=5)
- 6)      -8016 (18.4%) d@Group      -1600 (1600->0)     ui/gl/gl_stub_autogen_gl.cc (count=1)
~ 7)      -6424 (14.7%) d@Group      +1592 (4->1592)     v8/src/compiler/instruction.cc (count=4)
+ 8)      -4986 (11.4%) d@Group      +1438 (0->0)        {no path} (count=3)
~ 9)      -6398 (14.7%) d@Group      -1412 (15264->13852)  v8/src/compiler/machine-operator.cc (count=478)
~ 10)     -5182 (11.9%) d@Group      +1216 (288->1504)   v8/src/messages.cc (count=4)
~ 11)     -4022 (9.2%)  d@Group      +1160 (72->1220)    v8/src/wasm/function-body-decoder.cc (count=7)
~ 12)     -5126 (11.7%) d@Group      -1104 (1712->608)   blink/core/HTMLElementFactory.cpp (count=2)
~ 13)     -6158 (14.1%) d@Group      -1032 (2104->1072)  components/search_engines/template_url_prepopulate_data.cc (count=109)
~ 14)     -7066 (16.2%) d@Group      -908 (7464->6536)   {shared} (count=272)
~ 15)     -7914 (18.1%) d@Group      -848 (3616->2768)   third_party/sfntly/src/cpp/src/sfntly/table/truetype/glyph_table.cc (count=50)
~ 16)     -8726 (20.0%) d@Group      -812 (1544->732)    third_party/WebKit/Source/core/workers/WorkerGlobalScope.cpp (count=14)
~ 17)     -7998 (18.3%) d@Group      +728 (472->1200)    content/browser/renderer_host/compositor_impl_android.cc (count=4)
~ 18)     -8722 (20.0%) d@Group      -724 (1176->452)    third_party/WebKit/Source/core/workers/WorkletGlobalScope.cpp (count=8)
- 19)     -9426 (21.6%) d@Group      -704 (704->0)       third_party/WebKit/Source/core/workers/WorkerOrWorkletGlobalScope.cpp (count=6)
+ 20)     -8798 (20.1%) d@Group      +628 (0->620)       third_party/angle/src/compiler/translator/Operator.cpp (count=1)
~ 21)     -9418 (21.6%) d@Group      -620 (1564->944)    third_party/WebKit/Source/web/WebLocalFrameImpl.cpp (count=8)
+ 22)     -8810 (20.2%) d@Group      +608 (0->608)       third_party/WebKit/Source/core/html/HTMLTablePartElement.cpp (count=1)
~ 23)     -9414 (21.6%) d@Group      -604 (612->12)      third_party/WebKit/Source/core/dom/ExecutionContext.cpp (count=10)
+ 24)     -8866 (20.3%) d@Group      +548 (0->508)       components/sync/protocol/proto_enum_conversions.cc (count=19)
- 25)     -9378 (21.5%) d@Group      -512 (512->0)       blink/core/SVGElementFactory.cpp (count=1)
- 26)     -9882 (22.6%) d@Group      -504 (504->0)       third_party/sfntly/src/cpp/src/sfntly/table/{shared} (count=8)
~ 27)    -10386 (23.8%) d@Group      -504 (1096->580)    third_party/skia/src/jumper/SkJumper.cpp (count=7)
- 28)    -10882 (24.9%) d@Group      -496 (496->0)       third_party/sfntly/src/cpp/src/sfntly/table/bitmap/index_sub_table.cc (count=8)
~ 29)    -10394 (23.8%) d@Group      +488 (344->828)     third_party/webrtc/api/statstypes.cc (count=11)
+ 30)     -9918 (22.7%) d@Group      +476 (0->464)       net/quic/core/quic_error_codes.cc (count=2)
- 31)    -10374 (23.8%) d@Group      -456 (456->0)       third_party/sfntly/src/cpp/src/sfntly/table/bitmap/bitmap_glyph.cc (count=8)
- 32)    -10830 (24.8%) d@Group      -456 (456->0)       third_party/sfntly/src/cpp/src/sfntly/table/bitmap/glyph_metrics.cc (count=8)
~ 33)    -11286 (25.8%) d@Group      -456 (1560->1104)   third_party/sfntly/src/cpp/src/sfntly/table/truetype/loca_table.cc (count=23)
~ 34)    -10838 (24.8%) d@Group      +448 (948->1396)    third_party/WebKit/Source/core/svg/{shared} (count=24)
~ 35)    -10402 (23.8%) d@Group      +436 (20->456)      third_party/libxml/src/parser.c (count=3)
~ 36)    -10822 (24.8%) d@Group      -420 (1696->1276)   third_party/sfntly/src/cpp/src/sfntly/table/bitmap/index_sub_table_format1.cc (count=24)
~ 37)    -11242 (25.7%) d@Group      -420 (1696->1276)   third_party/sfntly/src/cpp/src/sfntly/table/bitmap/index_sub_table_format2.cc (count=24)
~ 38)    -11662 (26.7%) d@Group      -420 (1696->1276)   third_party/sfntly/src/cpp/src/sfntly/table/bitmap/index_sub_table_format3.cc (count=24)
~ 39)    -12082 (27.7%) d@Group      -420 (1696->1276)   third_party/sfntly/src/cpp/src/sfntly/table/bitmap/index_sub_table_format4.cc (count=24)
~ 40)    -12502 (28.6%) d@Group      -420 (1696->1276)   third_party/sfntly/src/cpp/src/sfntly/table/bitmap/index_sub_table_format5.cc (count=24)
~ 41)    -12914 (29.6%) d@Group      -412 (10936->10504)  v8/src/crankshaft/arm/lithium-arm.cc (count=127)
- 42)    -13314 (30.5%) d@Group      -400 (400->0)       third_party/WebKit/Source/core/html/forms/BaseTemporalInputType.cpp (count=1)
~ 43)    -13710 (31.4%) d@Group      -396 (7040->6636)   v8/src/compiler/simplified-operator.cc (count=223)
~ 44)    -13314 (30.5%) d@Group      +396 (624->1008)    v8/src/interface-descriptors.cc (count=27)
~ 45)    -12918 (29.6%) d@Group      +396 (312->692)     v8/src/objects.cc (count=17)
~ 46)    -12530 (28.7%) d@Group      +388 (40->416)      third_party/WebKit/Source/core/inspector/InspectorTraceEvents.cpp (count=3)
+ 47)    -12162 (27.8%) d@Group      +368 (0->352)       v8/src/heap/gc-tracer.cc (count=3)
+ 48)    -11802 (27.0%) d@Group      +360 (0->356)       third_party/angle/src/compiler/translator/Types.cpp (count=9)
~ 49)    -12146 (27.8%) d@Group      -344 (3440->3096)   gpu/skia_bindings/gl_bindings_skia_cmd_buffer.cc (count=87)
~ 50)    -12486 (28.6%) d@Group      -340 (1968->1616)   third_party/sfntly/src/cpp/src/sfntly/table/core/name_table.cc (count=33)