[cc] Cleanup: Modify description of BitmapContentLayerUpdater

R=ccameron@chromium.org
BUG=NONE
TEST=NONE(no functional change)

Review URL: https://codereview.chromium.org/125203007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243412 0039d316-1c4b-4281-b951-d872f2087c98

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 {