Update android_make to support both --gcc and --clang options.

gyp/common_conditions.gypi

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # conditions used in both common.gypi and skia.gyp in chromium
 #
 {
   'defines': [
     'SK_ALLOW_STATIC_GLOBAL_INITIALIZERS=<(skia_static_initializers)',
@@ skipping 637 matching lines @@
             'defines': [
               'SKIA_DLL',
               'SKIA_IMPLEMENTATION=1',
               # Needed until we fix https://bug.skia.org/2440 .
               'SK_SUPPORT_LEGACY_CLIPTOLAYERFLAG',
             ],
           }],
           [ 'skia_profile_enabled == 1', {
             'cflags': ['-g', '-fno-omit-frame-pointer', '-marm', '-mapcs'],
           }],
+          [ 'skia_clang_build', {
+            'cflags': [
+                '-Wno-unknown-warning-option', # Allows unknown warnings
+                # These flags that are on by default for only the android
+                # toolchain and no other platforms.
+                '-Wno-tautological-compare',
+                '-Wno-unused-command-line-argument',
+            ],
+          }],
         ],
       },
     ],
 
     [ 'skia_moz2d', {
       'defines': [
         # add flags here (e.g. SK_SUPPORT_LEGACY_...) needed by moz2d
       ],
     }],
 
     [ 'skia_command_buffer and skia_os == "linux"', {
       'ldflags': [
           '-Wl,-rpath,\$$ORIGIN/lib',
       ],
     }],
 
     [ 'skia_command_buffer and skia_os == "mac"', {
       'xcode_settings': {
           'LD_RUNPATH_SEARCH_PATHS': ['@executable_path/.'],
       },
     }],
 
   ], # end 'conditions'
   # The Xcode SYMROOT must be at the root. See build/common.gypi in chromium for more details
   'xcode_settings': {
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }