Changes subtreeShouldRenderToSeparateSurface logic to account for explicit clipping

cc/draw_properties.h

Index: cc/draw_properties.h
diff --git a/cc/draw_properties.h b/cc/draw_properties.h
index 3895ef0720ab675044c7f7f9d63142261ac8e3ed..5220bcd5a53d650d1c299cbaf5fdf79f332b655c 100644
--- a/cc/draw_properties.h
+++ b/cc/draw_properties.h
@@ -25,6 +25,7 @@ struct CC_EXPORT DrawProperties {
         , is_clipped(false)
         , render_target(0)
         , num_descendants_that_draw_content(0)
+        , num_descendants_that_draw_content_and_cant_clip_themselves(0)

[jamesr, 2012/12/14 21:48:54]

Hmm, what a mouthful!

I don't think we need a count here, we just need a bool.  For
num_desc.._that_draw_content we need a count since we have different behavior
for 0, 1, and 2+.  For clipping we only care about 0 and 1+

I think this might be shorter and clearer still if it was phrased as a positive
rather than a negative - i.e. "can_clip_self" or something like that?

     {
     }
 
@@ -77,6 +78,7 @@ struct CC_EXPORT DrawProperties {
 
     // Does not include this layer itself, only its children and descendants.
     int num_descendants_that_draw_content;
+    int num_descendants_that_draw_content_and_cant_clip_themselves;
 };
 
 }  // namespace cc