Complete disable_gl_rgb_format workaround for Mali-400 GPU

gpu/command_buffer/service/framebuffer_manager.h

Index: gpu/command_buffer/service/framebuffer_manager.h
diff --git a/gpu/command_buffer/service/framebuffer_manager.h b/gpu/command_buffer/service/framebuffer_manager.h
index 61019d5614bdaf64b02addeca00f2d0b74b1b42b..6e6ecd2671afd5054e9921b13dc98957ee3a2e5b 100644
--- a/gpu/command_buffer/service/framebuffer_manager.h
+++ b/gpu/command_buffer/service/framebuffer_manager.h
@@ -123,7 +123,7 @@ class GPU_EXPORT Framebuffer : public base::RefCounted<Framebuffer> {
 
   bool HasDepthAttachment() const;
   bool HasStencilAttachment() const;
-  GLenum GetDrawBufferInternalFormat() const;
+  GLenum GetColorAttachment0Format() const;
   GLenum GetReadBufferInternalFormat() const;
   // If the color attachment is a texture, returns its type; otherwise,
   // returns 0.