extensions_unittests also fails. Build failure happens on Linux in all configurations I've tried (debug/release, component/non-component).

The failure is in extensions:extensions_renderer_resources_grit, so everything depending on that fails (e.g., extensions/common) until chrome is build.

isolated error:

~/dev/c/w2/src % gn clean out_linux/test
~/dev/c/w2/src % ninja -C out_linux/test -j 9999 -l 40 extensions:extensions_renderer_resources_grit
ninja: Entering directory `out_linux/test'
[1/1] Regenerating ninja files
[71/72] ACTION //extensions:extensions_renderer_resources_grit(//build/toolchain/linux:clang_x64)
FAILED: gen/extensions/extensions_renderer_resources_stamp.d.stamp gen/extensions/grit/extensions_renderer_resources.h gen/extensions/extensions_renderer_resources.pak
python ../../tools/grit/grit.py -i ../../extensions/renderer/resources/extensions_renderer_resources.grd build -o gen/extensions --depdir . --depfile gen/extensions/extensions_renderer_resources_stamp.d --write-only-new=1 --depend-on-stamp -D _chromium -E CHROMIUM_BUILD=chromium -D desktop_linux -D toolkit_views -D use_aura -D use_nss_certs -D enable_media_router -E mojom_root=/usr/local/google/home/michaelpg/dev/c/w2/src/out_linux/test/gen -f ../../tools/gritsettings/resource_ids --assert-file-list=obj/extensions/extensions_renderer_resources_expected_outputs.txt
Error processing node <?xml version="1.0" encoding="UTF-8"?>
<include file="${mojom_root}\chrome\browser\media\router\mojo\media_controller.mojom.js" name="IDR_MEDIA_CONTROLLER_MOJOM_JS" type="BINDATA" use_base_dir="false" />
Traceback (most recent call last):
  File "../../tools/grit/grit.py", line 15, in <module>
    grit.grit_runner.Main(sys.argv[1:])
  File "/usr/local/google/home/michaelpg/dev/c/w2/src/tools/grit/grit/grit_runner.py", line 268, in Main
    toolobject.Run(options, args[1:])
  File "/usr/local/google/home/michaelpg/dev/c/w2/src/tools/grit/grit/tool/build.py", line 273, in Run
    self.Process()
  File "/usr/local/google/home/michaelpg/dev/c/w2/src/tools/grit/grit/tool/build.py", line 400, in Process
    self.ProcessNode(self.res, output, outfile)
  File "/usr/local/google/home/michaelpg/dev/c/w2/src/tools/grit/grit/tool/build.py", line 337, in ProcessNode
    formatted = formatter(node, output_node.GetLanguage(), output_dir=base_dir)
  File "/usr/local/google/home/michaelpg/dev/c/w2/src/tools/grit/grit/format/data_pack.py", line 45, in Format
    id, value = node.GetDataPackPair(lang, UTF8)
  File "/usr/local/google/home/michaelpg/dev/c/w2/src/tools/grit/grit/node/include.py", line 96, in GetDataPackPair
    data = util.ReadFile(filename, util.BINARY)
  File "/usr/local/google/home/michaelpg/dev/c/w2/src/tools/grit/grit/util.py", line 207, in ReadFile
    with open(filename, mode) as f:
IOError: [Errno 2] No such file or directory: u'/usr/local/google/home/michaelpg/dev/c/w2/src/out_linux/test/gen/chrome/browser/media/router/mojo/media_controller.mojom.js'
ninja: build stopped: subcommand failed.
~

One-line patch at https://codereview.chromium.org/2809303002/ fixes the problem without bringing in much more from chrome, thanks Devlin for the suggestion.

It seems adding "//chrome/browser/media/router:mojo_bindings_common__generator" will resolve the immediate problem (although it's a bad hack, similar to the mojo_bindings dep). It seems the mojom __generator rules aren't transitive, which is why we get the build failure.


takumif@ is working on a patch to move the resource Media Router mojom declarations out of extensions/renderer/resources/extensions_renderer_resources.grd, which should fix this bad dependency.

Re #5: ...__generator is the actually IDL->source rule, which the template defines a source_set() target for as well; I'd expect the latter to have the correct transitive public_deps.  What's the rationale for depending on the __generator rule directly?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/01d3aa8fc776bb4c2ca45d8e77e1f120e7d61f1b

commit 01d3aa8fc776bb4c2ca45d8e77e1f120e7d61f1b
Author: michaelpg <michaelpg@chromium.org>
Date: Wed Apr 12 01:13:58 2017

Fix extensions targets building without chrome

The extensions:extensions_renderer_resources_grit target fails to
build without building parts of chrome first, meaning that targets in
//extensions fail to build. This includes binaries like
extensions_unittests, but also anything that depends on
extensions/common and not chrome. The dependency was introduced in
https://codereview.chromium.org/2727123002 without knowing it would
cause build problems.

This change seems to ensure the additional necessary mojo files are
generated before being used, without introducing additional major
chrome dependencies on top of those already here.

Specifically, it ensures that
obj/extensions/extensions_renderer_resources.ninja includes the
mojo_bindings_common__* results.

BUG= 706786 
R=rdevlin.cronin@chromium.org

Review-Url: https://codereview.chromium.org/2809303002
Cr-Commit-Position: refs/heads/master@{#463870}

[modify] https://crrev.com/01d3aa8fc776bb4c2ca45d8e77e1f120e7d61f1b/extensions/BUILD.gn

Marking fixed, remaining work looks to be in  issue 704958 .