cc: Add traces for identification of raster buffer.

cc/raster/raster_buffer_provider.cc

Index: cc/raster/raster_buffer_provider.cc
diff --git a/cc/raster/raster_buffer_provider.cc b/cc/raster/raster_buffer_provider.cc
index 5cac14a45ccd177869b67f33a120d9171f2fa62e..e6735a9d483aa6211193d33ef3c64a20c687b3ba 100644
--- a/cc/raster/raster_buffer_provider.cc
+++ b/cc/raster/raster_buffer_provider.cc
@@ -53,7 +53,8 @@ void RasterBufferProvider::PlaybackToMemory(
     const gfx::Rect& canvas_playback_rect,
     float scale,
     const RasterSource::PlaybackSettings& playback_settings) {
-  TRACE_EVENT0("cc", "RasterBufferProvider::PlaybackToMemory");
+  TRACE_EVENT0("disabled-by-default-cc.debug",
+               "RasterBufferProvider::PlaybackToMemory");
 
   DCHECK(IsSupportedPlaybackToMemoryFormat(format)) << format;