Support cross compiling for armhf variant 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 1749 matching lines @@
       ['arm_version==7 and android_webview_build==0', {
         'arm_arch%': 'armv7-a',
         'arm_tune%': 'cortex-a8',
         'conditions': [
           ['arm_neon==1', {
             'arm_fpu%': 'neon',
           }, {
             'arm_fpu%': 'vfpv3-d16',
           }],
         ],
-        'arm_float_abi%': 'softfp',
+        'arm_float_abi%': 'hard',

[Sam Clegg, 2013/10/28 17:20:09]

Really I would have liked to remove this line completely and let the
compiler's default abi be used but removing cased problems at some
point in the build with '' being and invalid value for --mfloat-abi.

I could investigate further...

[ghost stip (do not use), 2013/10/28 18:17:02]

Looking at http://gcc.gnu.org/onlinedocs/gcc/ARM-Options.html I don't see a
'system' option for -mfloat-abi so I guess we'd have to eliminate the option
altogether to get the system type. I'm OK with hardcoding it here

         'arm_thumb%': 1,
       }],
 
       ['android_webview_build==1', {
         # The WebView build gets its cpu-specific flags from the Android build system.
         'arm_arch%': '',
         'arm_tune%': '',
         'arm_fpu%': '',
         'arm_float_abi%': '',
         'arm_thumb%': 0,
@@ skipping 2942 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',
   },
 }