Set default cross compiler for ARM/linux builds.

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 5578 matching lines @@
       ],
     }],
     ['OS=="linux" and target_arch=="mipsel"', {
       'make_global_settings': [
         ['CC', '<(sysroot)/../bin/mipsel-linux-gnu-gcc'],
         ['CXX', '<(sysroot)/../bin/mipsel-linux-gnu-g++'],
         ['CC.host', '<!(which gcc)'],
         ['CXX.host', '<!(which g++)'],
       ],
     }],
+    ['OS=="linux" and target_arch=="arm" and host_arch!="arm" and chromeos==0 and clang==0', {
+      # Set default ARM cross compiling on linux.  These can be overridden
+      # using CC/CXX/etc environment variables.
+      'make_global_settings': [
+        ['CC', '<!(which arm-linux-gnueabihf-gcc)'],
+        ['CXX', '<!(which arm-linux-gnueabihf-g++)'],
+        ['CC.host', '<!(which gcc)'],
+        ['CXX.host', '<!(which g++)'],
+      ],
+    }],
 
     # TODO(yyanagisawa): supports GENERATOR==make
     #  make generator doesn't support CC_wrapper without CC
     #  in make_global_settings yet.
     ['use_goma==1 and ("<(GENERATOR)"=="ninja" or clang==1)', {
       'make_global_settings': [
        ['CC_wrapper', '<(gomadir)/gomacc'],
        ['CXX_wrapper', '<(gomadir)/gomacc'],
        ['CC.host_wrapper', '<(gomadir)/gomacc'],
        ['CXX.host_wrapper', '<(gomadir)/gomacc'],
@@ skipping 62 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',
   },
 }