Improve CopyTex{Sub}Image2D format validation.

gpu/command_buffer/common/gles2_cmd_utils.h

Index: gpu/command_buffer/common/gles2_cmd_utils.h
diff --git a/gpu/command_buffer/common/gles2_cmd_utils.h b/gpu/command_buffer/common/gles2_cmd_utils.h
index 267c0413af312bba055ab9657b062c71cbb2dd49..c9589b67b1cb167c0850a6935e0944714e4b27dd 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.h
+++ b/gpu/command_buffer/common/gles2_cmd_utils.h
@@ -221,6 +221,10 @@ class GLES2_UTILS_EXPORT GLES2Util {
   static bool IsIntegerFormat(uint32_t internal_format);
   static bool IsFloatFormat(uint32_t internal_format);
 
+  static bool IsSizedColorFormat(uint32_t internal_format);
+  static void GetColorFormatComponentSizes(
+      uint32_t internal_format, uint32_t type, int* r, int* g, int* b, int* a);
+
   // Computes the data size for certain gl commands like glUniform.
   static bool ComputeDataSize(uint32_t count,
                               size_t size,