[cc] Trace detailed tile info when --trace-all-rendered-frames

cc/picture_layer_tiling.cc

Index: cc/picture_layer_tiling.cc
diff --git a/cc/picture_layer_tiling.cc b/cc/picture_layer_tiling.cc
index d90eb42782f82c117f3c7898a6374c655f8c5aab..81b468e3e265ce6bf0b99175d0069fa0b4ff6569 100644
--- a/cc/picture_layer_tiling.cc
+++ b/cc/picture_layer_tiling.cc
@@ -435,6 +435,11 @@ void PictureLayerTiling::UpdateTilePriorities(
           resolution_,
           time_to_visible_in_seconds,
           distance_to_visible_in_pixels);
+      bool clipped;
+      priority.set_current_screen_quad(
+          MathUtil::projectQuad(current_screen_transform,

[shawnsingh, 2013/02/01 19:39:22]

First, are you sure we want project here?  This is mapping "forward" from local
space to screen, so map should be good enough.  (If mapQuad doesn't exist, we
can consider adding it back, I may have left it out for now to make sure we dont
use it for non-debugging code and shoot ourselves in the foot with more clipping
issues)

Second, yeah this will definitely hurt performance.  Is it possible to pull all
this out into a completely separate walk through tiles that does not get called
unless we want to serialize?

Otherwise, maybe we need to for now just #define it.  I'm still unfamiliar with
the tile priority code, but I suspect this is pretty hot code path and even an
if (serializeStuff) condition might be worth avoiding, right?

+                                gfx::QuadF(tile_bounds),
+                                clipped));
       tile->set_priority(tree, priority);
     }
   }
@@ -472,6 +477,11 @@ void PictureLayerTiling::UpdateTilePriorities(
           resolution_,
           time_to_visible_in_seconds,
           distance_to_visible_in_pixels);
+      bool clipped;
+      priority.set_current_screen_quad(
+          MathUtil::projectQuad(current_screen_transform,
+                                gfx::QuadF(tile_bounds),
+                                clipped));
       tile->set_priority(tree, priority);
     }
   }