Yep, seems likely to be r431741 - Brett, can you take a look?

FWIW, I hit it in a different place:
[637/8240] CXX obj/chrome/browser/apps/app_shim/app_shim/app_shim_handler_mac.o
FAILED: obj/chrome/browser/apps/app_shim/app_shim/app_shim_handler_mac.o 
/Users/schenney/goma/gomacc ../../third_party/llvm-build/Release+Asserts/bin/clang++ -MMD -MF obj/chrome/browser/apps/app_shim/app_shim/app_shim_handler_mac.o.d -DV8_DEPRECATION_WARNINGS -DENABLE_NOTIFICATIONS -DENABLE_PDF=1 -DNO_TCMALLOC -DUSE_EXTERNAL_POPUP_MENU=1 -DDISABLE_NACL -DENABLE_TASK_MANAGER=1 -DENABLE_THEMES=1 -DFULL_SAFE_BROWSING -DSAFE_BROWSING_CSD -DSAFE_BROWSING_DB_LOCAL -DCHROMIUM_BUILD -DENABLE_MEDIA_ROUTER=1 -DFIELDTRIAL_TESTING_ENABLED -DCR_CLANG_REVISION=287780-2 -DCR_XCODE_VERSION=0511 -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D_FORTIFY_SOURCE=2 -DCOMPONENT_BUILD -D__ASSERT_MACROS_DEFINE_VERSIONS_WITHOUT_UNDERSCORE=0 -DNDEBUG -DNVALGRIND -DDYNAMIC_ANNOTATIONS_ENABLED=0 -DSK_IGNORE_DW_GRAY_FIX -DSK_IGNORE_LINEONLY_AA_CONVEX_PATH_OPTS -DSKIA_DLL -DGR_GL_IGNORE_ES3_MSAA=0 -DSK_SUPPORT_GPU=1 -DSK_BUILD_FOR_MAC -DV8_USE_EXTERNAL_STARTUP_DATA -DU_USING_ICU_NAMESPACE=0 -DU_ENABLE_DYLOAD=0 -DICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE -DMESA_EGL_NO_X11_HEADERS -DGOOGLE_PROTOBUF_NO_RTTI -DGOOGLE_PROTOBUF_NO_STATIC_INITIALIZER -DHAVE_PTHREAD -DPROTOBUF_USE_DLLS -DBORINGSSL_SHARED_LIBRARY -DUSING_V8_SHARED -I../.. -Igen -I../../third_party/khronos -I../../gpu -I../../third_party/libwebp -I../../skia/config -I../../skia/ext -I../../third_party/skia/include/c -I../../third_party/skia/include/config -I../../third_party/skia/include/core -I../../third_party/skia/include/effects -I../../third_party/skia/include/images -I../../third_party/skia/include/lazy -I../../third_party/skia/include/pathops -I../../third_party/skia/include/pdf -I../../third_party/skia/include/pipe -I../../third_party/skia/include/ports -I../../third_party/skia/include/utils -I../../third_party/skia/include/gpu -I../../third_party/skia/src/gpu -I../../third_party/skia/src/sksl -I../../third_party/icu/source/common -I../../third_party/icu/source/i18n -I../../third_party/mesa/src/include -I../../third_party/libwebm/source -I../../third_party/protobuf/src -Igen/protoc_out -I../../third_party/protobuf/src -I../../third_party/boringssl/src/include -Igen -I../../third_party/ced/src -I../../third_party/WebKit -Igen/third_party/WebKit -I../../v8/include -Igen/v8/include -fno-strict-aliasing -fstack-protector -fcolor-diagnostics -arch x86_64 -Wall -Werror -Wextra -Wpartial-availability -Wno-missing-field-initializers -Wno-unused-parameter -Wno-c++11-narrowing -Wno-covered-switch-default -Wno-deprecated-register -Wno-unneeded-internal-declaration -Wno-inconsistent-missing-override -Wno-shift-negative-value -Wno-undefined-var-template -Wno-nonportable-include-path -Wno-address-of-packed-member -O2 -gdwarf-2 -isysroot /Users/schenney/development/chromium_1/src/build/mac_files/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk -mmacosx-version-min=10.9 -fvisibility=hidden -Xclang -load -Xclang ../../third_party/llvm-build/Release+Asserts/lib/libFindBadConstructs.dylib -Xclang -add-plugin -Xclang find-bad-constructs -Wheader-hygiene -Wstring-conversion -fno-threadsafe-statics -fvisibility-inlines-hidden -std=c++11 -stdlib=libc++ -fno-rtti -fno-exceptions -c ../../chrome/browser/apps/app_shim/app_shim_handler_mac.cc -o obj/chrome/browser/apps/app_shim/app_shim/app_shim_handler_mac.o
In file included from ../../chrome/browser/apps/app_shim/app_shim_handler_mac.cc:17:
../../chrome/browser/chrome_notification_types.h:9:10: fatal error: 'extensions/features/features.h' file not found
#include "extensions/features/features.h"
         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

There seems to be missing build dependencies. Building again fixes the issue.

This also came up at https://groups.google.com/a/chromium.org/forum/#!msg/chromium-dev/RJ1JIryjaMU/

Note that doing things like

$ rm out/gn_Debug/gen/extensions/features/features.h && touch extensions/browser/mojo/keep_alive_impl.cc && ninja -C out/gn_Debug -v obj/extensions/browser/mojo/mojo/keep_alive_impl.o

will not reproduce this. I.e. ninja will always regenerate the header before attempting to compile keep_alive_impl.cc. Same for app_shim_handler_mac.cc.

However, deleting out/gn_Debug/.ninja_deps in addition *does* reproduce the problem (after compiling 1875 other targets -- mostly v8 :/).

After that, `ninja -C out/gn_Debug -v obj/extensions/browser/mojo/mojo/keep_alive_impl.o` will keep failing.

fix: //extensions/browser/mojo should depend on //extensions/common (although it's not the file failing in the comments above, e/b/mojo/service_registration.cc includes stuff from //extensions/common, so the dep is valid). Then `ninja -C out/gn_Debug -v obj/extensions/browser/mojo/mojo/keep_alive_impl.o` works.


For //chrome/browser/apps/app_shim it's a similar story. Although app_shim_handler_mac.cc doesn't depend on extensions, extension_app_shim_handler_mac in the same target does depend on both //extensions/common and //extensions/browser.

r436385 removed //extensions/browser/mojo

fix for app_shim is in https://codereview.chromium.org/2548403003/

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6ee456f20d1987d8dfa75f1c431722111eb4ca2a

commit 6ee456f20d1987d8dfa75f1c431722111eb4ca2a
Author: tapted <tapted@chromium.org>
Date: Tue Dec 06 06:33:02 2016

Add missing //extensions/ deps for app_shim.

This currently causes build flakes the first time an output directory
is built, since it depends transitively on a generated header. Ninja is
smart enough add a dependency to the generated header once the generated
file exists, but doesn't do that on the initial build.

Although the errors blame other files, chrome/browser/apps/app_shim/'s
extension_app_shim_handler_mac.cc includes files from extensions/common.
The source set should have this dependency. This fixes the problem.

There are other missing dependencies, such as the path of files named in
the compile error. However, they can't be added without creating a
dependency loop, since its the missing dependencies that depend on these
targets via a source_set.

BUG= 665694 

Review-Url: https://codereview.chromium.org/2548403003
Cr-Commit-Position: refs/heads/master@{#436540}

[modify] https://crrev.com/6ee456f20d1987d8dfa75f1c431722111eb4ca2a/chrome/browser/apps/app_shim/BUILD.gn