cc: Rename visible_content_rect and content stuff on quads.

cc/layers/append_quads_data.h

Index: cc/layers/append_quads_data.h
diff --git a/cc/layers/append_quads_data.h b/cc/layers/append_quads_data.h
index 50f58775d48a3c7e101f6d6da466123a814eec2e..45b0c17b20f4f929542f507e17d7dc14fad61cee 100644
--- a/cc/layers/append_quads_data.h
+++ b/cc/layers/append_quads_data.h
@@ -14,7 +14,7 @@ struct AppendQuadsData {
   AppendQuadsData()
       : num_incomplete_tiles(0),
         num_missing_tiles(0),
-        visible_content_area(0),
+        visible_layer_area(0),
         approximated_visible_content_area(0),
         checkerboarded_visible_content_area(0) {}
 
@@ -23,7 +23,7 @@ struct AppendQuadsData {
   // Set by the layer appending quads.
   int64 num_missing_tiles;
   // Set by the layer appending quads.
-  int64 visible_content_area;
+  int64 visible_layer_area;
   // Set by the layer appending quads.
   int64 approximated_visible_content_area;
   // Set by the layer appending quads.