cc: Rename visible_content_rect and content stuff on quads.

cc/quads/draw_polygon.h

Index: cc/quads/draw_polygon.h
diff --git a/cc/quads/draw_polygon.h b/cc/quads/draw_polygon.h
index b94ff1ef777185a31a37c593c30f6fb7bc317bd7..93c36024fc24562b5303e3b30591ddd77543c411 100644
--- a/cc/quads/draw_polygon.h
+++ b/cc/quads/draw_polygon.h
@@ -29,7 +29,7 @@ class CC_EXPORT DrawPolygon {
               const gfx::Vector3dF& normal,
               int draw_order_index = 0);
   DrawPolygon(const DrawQuad* original_ref,
-              const gfx::RectF& visible_content_rect,
+              const gfx::RectF& visible_layer_rect,
               const gfx::Transform& transform,
               int draw_order_index = 0);