Implement Discard and EnsureBackbufferCHROMIUM using command buffer instead of IPC.

gpu/command_buffer/client/gles2_cmd_helper_autogen.h

Index: gpu/command_buffer/client/gles2_cmd_helper_autogen.h
diff --git a/gpu/command_buffer/client/gles2_cmd_helper_autogen.h b/gpu/command_buffer/client/gles2_cmd_helper_autogen.h
index 77e1ff252c2fbfe3432c5a81ecbf6708432a328a..4f99c689de7fb671e55e9797a0650606a4c50b9b 100644
--- a/gpu/command_buffer/client/gles2_cmd_helper_autogen.h
+++ b/gpu/command_buffer/client/gles2_cmd_helper_autogen.h
@@ -1744,5 +1744,21 @@
     }
   }
 
+  void DiscardBackbufferCHROMIUM() {
+    gles2::DiscardBackbufferCHROMIUM* c =
+        GetCmdSpace<gles2::DiscardBackbufferCHROMIUM>();
+    if (c) {
+      c->Init();
+    }
+  }
+
+  void EnsureBackbufferCHROMIUM() {
+    gles2::EnsureBackbufferCHROMIUM* c =
+        GetCmdSpace<gles2::EnsureBackbufferCHROMIUM>();
+    if (c) {
+      c->Init();
+    }
+  }
+
 #endif  // GPU_COMMAND_BUFFER_CLIENT_GLES2_CMD_HELPER_AUTOGEN_H_