Add EXT_color_buffer_half_float extension support in GPU commandbuffer service.

gpu/command_buffer/common/gles2_cmd_utils.cc

Index: gpu/command_buffer/common/gles2_cmd_utils.cc
diff --git a/gpu/command_buffer/common/gles2_cmd_utils.cc b/gpu/command_buffer/common/gles2_cmd_utils.cc
index 25eafcd8a267fdf55826ac44a5120e77822578b0..88e9158e526d45b76770180cae54e99f38f80f8b 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.cc
+++ b/gpu/command_buffer/common/gles2_cmd_utils.cc
@@ -232,6 +232,8 @@ int GLES2Util::GLGetNumValuesReturned(int id) const {
     //    GL_EXT_multisampled_render_to_texture
     case GL_FRAMEBUFFER_ATTACHMENT_TEXTURE_SAMPLES_EXT:
       return 1;
+    case GL_FRAMEBUFFER_ATTACHMENT_COMPONENT_TYPE_EXT:
+      return 1;
 
     // -- glGetProgramiv
     case GL_DELETE_STATUS:
@@ -469,6 +471,14 @@ size_t GLES2Util::RenderbufferBytesPerPixel(int format) {
     case GL_RGBA8_OES:
     case GL_DEPTH_COMPONENT24_OES:
       return 4;
+    case GL_RGB16F_EXT:
+      return 6;
+    case GL_RGBA16F_EXT:
+      return 8;
+    case GL_RGB32F_EXT:
+      return 12;
+    case GL_RGBA32F_EXT:
+      return 16;
     default:
       return 0;
   }