remove unecessary warnings from third_party code

platform_tools/android/gyp/dependencies.gypi

 # This GYP file stores the dependencies necessary to build Skia on the Android
 # platform. The OS doesn't provide many stable libraries as part of the
 # distribution so we have to build a few of them ourselves.
 #
 # NOTE: We tried adding the gyp file to the android/ directory at the root of
 # the Skia repo, but that resulted in the generated makefiles being created
 # outside of the out directory. We may be able to move the bulk of this gyp
 # to the /android directory and put a simple shim here, but that has yet to be
 # tested.
 
 {
   'variables': {
     'skia_warnings_as_errors': 0,
   },
   'targets': [
     {
       'target_name': 'cpu_features',
       'type': 'static_library',
       'direct_dependent_settings': {
         'include_dirs': [
           '../third_party/cpufeatures',
         ],
       },
       'sources': [
         '../third_party/cpufeatures/cpu-features.c',
         '../third_party/cpufeatures/cpu-features.h',
       ],
+      'cflags': [
+        '-w',
+      ],
     },
     {
       'target_name': 'expat',
       'type': 'static_library',
       'sources': [
         '../third_party/externals/expat/lib/xmlparse.c',
         '../third_party/externals/expat/lib/xmlrole.c',
         '../third_party/externals/expat/lib/xmltok.c',
       ],
       'include_dirs': [
@@ skipping 127 matching lines @@
         '../third_party/externals/jpeg/jquant1.c',
         '../third_party/externals/jpeg/jquant2.c',
         '../third_party/externals/jpeg/jutils.c',
         '../third_party/externals/jpeg/jmemmgr.c',
         '../third_party/externals/jpeg/jmem-android.c', # ashmem is also available
       ],
       'include_dirs': [
         '../third_party/externals/jpeg',
       ],
       'cflags': [
+        '-w',
         '-fvisibility=hidden',
         '-DAVOID_TABLES',
         '-O3',
         '-fstrict-aliasing',
         '-fprefetch-loop-arrays',
         '-DANDROID_TILE_BASED_DECODE',
       ],
-      'cflags!': [
-        '-Wall',
-      ],
       'direct_dependent_settings': {
         'include_dirs': [
           '../third_party/externals/jpeg',
         ],
       }
     },
     {
       # This target is a dependency for all console-type Skia applications which
       # will run on Android.  Since Android requires us to load native code in
       # shared libraries, we need a common entry point to wrap around main().
@@ skipping 44 matching lines @@
           }],
         ],
         'sources': [
           '../app/jni/com_skia_SkiaSampleRenderer.cpp',
         ],
       },
 
     },
   ]
 }