Roll src/third_party/android_tools 5722f90:6957ab0

build/common.gypi

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 3938 matching lines @@
                 'cflags': [
                   '-msse2',
                   '-mfpmath=sse',
                   '-mmmx',  # Allows mmintrin.h for MMX intrinsics.
                   '-m32',
                 ],
                 'ldflags': [
                   '-m32',
                 ],
                 'conditions': [
-                  # Use gold linker for Android ia32 target.
                   ['OS=="android"', {
+                    # Use gold linker for Android ia32 target.
                     'ldflags': [
                       '-fuse-ld=gold',
                     ],
+                    # Use -mstackrealign due to a bug on ia32 Jelly Bean.
+                    # See crbug.com/521527

[Nico, 2015/08/18 23:24:52]

https://android-review.googlesource.com/#/c/110770/ sounds like the NDK expects
things to work without this flag. Why do we need this flag?

[Fabrice (no longer in Chrome), 2015/08/18 23:30:59]

My best guess is that there is something wrong in one of our x86 assembly files
and the stack gets misaligned at some point. That seems to trigger a crash on
Android x86 Jelly Bean, but not on any other Android x86 versions. Maybe there
is also something wrong with x86 JB system libraries? I honestly am not familiar
enough with the x86 ABI to figure it out and the bug also causes the stack trace
to become garbage, making tracking the underlying issue hard.

[Nico, 2015/08/18 23:35:59]

Shouldn't the comment be more along the lines of "Figure out why this is needed,
fix, and remove this flag" then?

+                    'cflags': [
+                      '-mstackrealign',
+                    ],
                   }],
                 ],
               }],
             ],
           }],
           ['target_arch=="x64"', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'conditions': [
                   # Use gold linker for Android x64 target.
@@ skipping 2345 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }