[cc] Cleanup: Modify description of BitmapContentLayerUpdater

cc/resources/bitmap_content_layer_updater.h

Index: cc/resources/bitmap_content_layer_updater.h
diff --git a/cc/resources/bitmap_content_layer_updater.h b/cc/resources/bitmap_content_layer_updater.h
index ecc0c153b7fcc4be10d805af7554f331f12f1345..f618655bbfcb3224f14e3e1d8b2c96d1cb89d10e 100644
--- a/cc/resources/bitmap_content_layer_updater.h
+++ b/cc/resources/bitmap_content_layer_updater.h
@@ -18,8 +18,9 @@ class LayerPainter;
 class RenderingStatsInstrumenation;
 
 // This class rasterizes the content_rect into a skia bitmap canvas. It then
-// updates textures by copying from the canvas into the texture, using
-// MapSubImage if possible.
+// creates a ResourceUpdate with this bitmap canvas and inserts the
+// ResourceBundle to the provided ResourceUpdateQueue. Actual texture uploading
+// is done by ResourceUpdateController.
 class CC_EXPORT BitmapContentLayerUpdater : public ContentLayerUpdater {
  public:
   class Resource : public LayerUpdater::Resource {