Don't use clang by default when cross building for ARM/linux.

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 1762 matching lines @@
             'enable_mpeg2ts_stream_parser%': 1,
             'video_hole%': 1,
           }],
         ],
       }],
       ['android_webview_build==1 or android_webview_telemetry_build==1', {
         # When building the WebView in the Android tree, jarjar will remap all
         # the class names, so the JNI generator needs to know this.
         'jni_generator_jarjar_file': '../android_webview/build/jarjar-rules.txt',
       }],
-      ['OS=="linux" and target_arch!="mipsel"', {
+      ['OS=="linux" and target_arch!="mipsel" and target_arch!="arm"', {

[Mark Seaborn, 2014/07/22 22:23:31]

Does this affect Chrome OS, or do they set the compiler in some way that
bypasses this (e.g. by setting clang=0)?

[Nico, 2014/07/22 22:25:00]

I made the chromeos chrome.ebuild explicitly set clang=0

         # TODO(thakis): This is here to measure perf for a while.
         'clang%': 1,
       }],  # OS=="mac"
       ['OS=="mac"', {
         'conditions': [
           # All Chrome builds have breakpad symbols, but only process the
           # symbols from official builds.
           ['(branding=="Chrome" and buildtype=="Official")', {
             'mac_strip_release%': 1,
           }],
@@ skipping 2467 matching lines @@
           ['binutils_version>=223', {
             # Newer binutils don't set DT_RPATH unless you disable "new" dtags
             # and the new DT_RUNPATH doesn't work without --no-as-needed flag.
             # FIXME(mithro): Figure out the --as-needed/--no-as-needed flags
             # inside this file to allow usage of --no-as-needed and removal of
             # this flag.
             'ldflags': [
               '-Wl,--disable-new-dtags',
             ],
           }],
+          ['gcc_version>=46 and gcc_version<48 and clang==0', {

[Mark Seaborn, 2014/07/22 22:23:31]

Can you add some comments here?  I can't really tell what this is for.

+            'target_conditions': [
+              ['_toolset=="target"', {
+                'cflags_cc': [
+                  '-std=gnu++0x',
+                  '-fpermissive',
+                ],
+              }],
+            ],
+          }],
           ['gcc_version>=48 and clang==0', {
             'target_conditions': [
               ['_toolset=="target"', {
                 'cflags_cc': [
                   '-std=gnu++11',
                   # See comment for -Wno-c++11-narrowing.
                   '-Wno-narrowing',
                   # TODO(thakis): Remove, http://crbug.com/263960
                   '-Wno-literal-suffix',
                 ],
@@ skipping 1374 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',
   },
 }