Added GL_CHROMIUM_trace_marker feature as well as gpu_toplevel markers.

webkit/common/gpu/webgraphicscontext3d_impl.h

Index: webkit/common/gpu/webgraphicscontext3d_impl.h
diff --git a/webkit/common/gpu/webgraphicscontext3d_impl.h b/webkit/common/gpu/webgraphicscontext3d_impl.h
index 3ed0dd97269b502022db5751f1d0417f7aa6e72e..8be98c30efcf08b815a522eb0a0b7a20e3869ebe 100644
--- a/webkit/common/gpu/webgraphicscontext3d_impl.h
+++ b/webkit/common/gpu/webgraphicscontext3d_impl.h
@@ -494,6 +494,9 @@ class WEBKIT_GPU_EXPORT WebGraphicsContext3DImpl
   virtual void uniformValuebufferCHROMIUM(WGC3Dint location,
                                           WGC3Denum target,
                                           WGC3Denum subscription);
+  virtual void traceBeginCHROMIUM(const WGC3Dchar* category_name,
+                                  const WGC3Dchar* trace_name);
+  virtual void traceEndCHROMIUM();
 
   virtual void insertEventMarkerEXT(const WGC3Dchar* marker);
   virtual void pushGroupMarkerEXT(const WGC3Dchar* marker);