cc: Replace recorded region with direct map lookup

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 9ec6fac5c412c7dff2a8c98c38dfecaa0625ad26..f06bd6a72b986e2eb32a8ab829969a5acc0f7bbe 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -864,8 +864,7 @@ PictureLayerTiling* PictureLayerImpl::AddTiling(float contents_scale) {
 
   PictureLayerTiling* tiling = tilings_->AddTiling(contents_scale);
 
-  const Region& recorded = pile_->recorded_region();
-  DCHECK(!recorded.IsEmpty());
+  DCHECK(pile_->HasRecordings());
 
   if (twin_layer_ &&
       twin_layer_->ShouldUseGpuRasterization() == ShouldUseGpuRasterization())
@@ -1177,7 +1176,7 @@ void PictureLayerImpl::ResetRasterScale() {
 bool PictureLayerImpl::CanHaveTilings() const {
   if (!DrawsContent())
     return false;
-  if (pile_->recorded_region().IsEmpty())
+  if (!pile_->HasRecordings())
     return false;
   return true;
 }
@@ -1221,11 +1220,6 @@ void PictureLayerImpl::AsValueInto(base::DictionaryValue* state) const {
   state->Set("pictures", pile_->AsValue().release());
   state->Set("invalidation", invalidation_.AsValue().release());
 
-  Region unrecorded_region(gfx::Rect(pile_->size()));
-  unrecorded_region.Subtract(pile_->recorded_region());
-  if (!unrecorded_region.IsEmpty())
-    state->Set("unrecorded_region", unrecorded_region.AsValue().release());
-
   scoped_ptr<base::ListValue> coverage_tiles(new base::ListValue);
   for (PictureLayerTilingSet::CoverageIterator iter(tilings_.get(),
                                                     contents_scale_x(),