Upgrade Tex{Sub}Image{2|3}D to handle ES3 unpack parameters.

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 93a90002c851e1a12322088ae6b879a5cfa71092..adf0c2d4dd77d799228a29a3a9ad7e0f4178f434 100644
--- a/gpu/command_buffer/common/gles2_cmd_utils.cc
+++ b/gpu/command_buffer/common/gles2_cmd_utils.cc
@@ -795,6 +795,10 @@ uint32_t GLES2Util::GetElementCountForUniformType(int type) {
   }
 }
 
+size_t GLES2Util::GetGLTypeSizeForTextures(uint32_t type) {
+  return static_cast<size_t>(BytesPerElement(type));
+}
+
 size_t GLES2Util::GetGLTypeSizeForBuffers(uint32_t type) {
   switch (type) {
     case GL_BYTE: