Remove SupportsWeakPtr inheritance from GLES2Decoder

gpu/command_buffer/service/gles2_cmd_decoder_mock.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder_mock.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder_mock.cc b/gpu/command_buffer/service/gles2_cmd_decoder_mock.cc
index d7da998daf93fefd761648e0960d9dc66b692ca3..5750b7e1f96b2ad6b6d702eb1b45c8d6384a9697 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder_mock.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder_mock.cc
@@ -9,8 +9,7 @@
 namespace gpu {
 namespace gles2 {
 
-MockGLES2Decoder::MockGLES2Decoder()
-    : GLES2Decoder() {
+MockGLES2Decoder::MockGLES2Decoder() : GLES2Decoder(), weak_ptr_factory_(this) {
   ON_CALL(*this, GetCommandName(testing::_))
       .WillByDefault(testing::Return(""));
   ON_CALL(*this, MakeCurrent())
@@ -27,5 +26,9 @@ error::Error MockGLES2Decoder::FakeDoCommands(unsigned int num_commands,
       num_commands, buffer, num_entries, entries_processed);
 }
 
+base::WeakPtr<GLES2Decoder> MockGLES2Decoder::AsWeakPtr() {
+  return weak_ptr_factory_.GetWeakPtr();
+}
+
 }  // namespace gles2
 }  // namespace gpu