Add EXT_color_buffer_half_float extension support in GPU commandbuffer service.

gpu/gpu.gyp

 # 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.
 
 {
   'variables': {
     'nacl_win64_target': 0,
   },
   'includes': [
     'gpu_common.gypi',
@@ skipping 260 matching lines @@
       ],
       'sources': [
         '<@(gles2_c_lib_source_files)',
         'command_buffer/client/gpu_memory_buffer_mock.cc',
         'command_buffer/client/gpu_memory_buffer_mock.h',
         'command_buffer/client/image_factory_mock.cc',
         'command_buffer/client/image_factory_mock.h',
         'command_buffer/tests/gl_bind_uniform_location_unittest.cc',
         'command_buffer/tests/gl_chromium_framebuffer_multisample_unittest.cc',
         'command_buffer/tests/gl_copy_texture_CHROMIUM_unittest.cc',
+        'command_buffer/tests/gl_ext_color_buffer_half_float_unittest.cc',
         'command_buffer/tests/gl_depth_texture_unittest.cc',
         'command_buffer/tests/gl_gpu_memory_buffer_unittests.cc',
         'command_buffer/tests/gl_lose_context_chromium_unittests.cc',
         'command_buffer/tests/gl_manager.cc',
         'command_buffer/tests/gl_manager.h',
         'command_buffer/tests/gl_pointcoord_unittest.cc',
         'command_buffer/tests/gl_program_unittests.cc',
         'command_buffer/tests/gl_query_unittests.cc',
         'command_buffer/tests/gl_readback_unittests.cc',
         'command_buffer/tests/gl_shared_resources_unittests.cc',
@@ skipping 255 matching lines @@
             'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)gl_tests<(SHARED_LIB_SUFFIX)',
           },
           'includes': [
             '../build/apk_test.gypi',
           ],
         },
       ],
     }],
   ],
 }