cc: Replace recorded region with direct map lookup

cc/resources/picture_pile.cc

Index: cc/resources/picture_pile.cc
diff --git a/cc/resources/picture_pile.cc b/cc/resources/picture_pile.cc
index 35d026f225ddb6a3a245048da2ee9657bc504092..e82a23e0fe4303bf1fe08ed1a0b2d5a2e3c8e855 100644
--- a/cc/resources/picture_pile.cc
+++ b/cc/resources/picture_pile.cc
@@ -164,6 +164,8 @@ bool PicturePile::Update(
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord);
+  recorded_viewport_ = interest_rect;
+  recorded_viewport_.Intersect(gfx::Rect(size()));
 
   bool invalidated = false;
   for (Region::Iterator i(invalidation); i.has_rect(); i.next()) {
@@ -201,17 +203,20 @@ bool PicturePile::Update(
     if (info.NeedsRecording(frame_number, distance_to_visible)) {
       gfx::Rect tile = tiling_.TileBounds(key.first, key.second);
       invalid_tiles.push_back(tile);
+    } else if (!info.GetPicture() && recorded_viewport_.Intersects(rect)) {

[danakj, 2014/03/18 20:11:24]

Or, one question: This bugfix didn't change any test expectations. Should we
have a test where something doesn't NeedsRecording but has a picture?

[enne (OOO), 2014/03/18 20:13:23]

This is hard to test, as this is a performance and not a correctness fix.  It
would lead to more often having an empty rect here and falling back to the map
lookup.

[danakj, 2014/03/18 20:27:50]

Is this the case that the tile in the interest rect isn't invalidated? This
being wrong, wouldn't it make use clear the rect every time some tile isn't
invalidated? Can we test that isn't the case?

+      // Recorded viewport is just an optimization for a fully recorded
+      // interest rect.  In this case, a tile in that rect has declined
+      // to be recorded (probably due to frequent invalidations).
+      // TODO(enne): Shrink the recorded_viewport_ rather than clearing.
+      recorded_viewport_ = gfx::Rect();
     }
   }
 
   std::vector<gfx::Rect> record_rects;
   ClusterTiles(invalid_tiles, &record_rects);
 
-  if (record_rects.empty()) {
-    if (invalidated)
-      UpdateRecordedRegion();
+  if (record_rects.empty())
     return invalidated;
-  }
 
   for (std::vector<gfx::Rect>::iterator it = record_rects.begin();
        it != record_rects.end();
@@ -247,6 +252,8 @@ bool PicturePile::Update(
       stats_instrumentation->AddRecord(best_duration, recorded_pixel_count);
     }
 
+    bool found_tile_for_recorded_picture = false;
+
     bool include_borders = true;
     for (TilingData::Iterator it(&tiling_, record_rect, include_borders); it;
          ++it) {
@@ -255,11 +262,14 @@ bool PicturePile::Update(
       if (record_rect.Contains(tile)) {
         PictureInfo& info = picture_map_[key];
         info.SetPicture(picture);
+        found_tile_for_recorded_picture = true;
       }
     }
+    DCHECK(found_tile_for_recorded_picture);
   }
 
-  UpdateRecordedRegion();
+  has_any_recordings_ = true;
+  DCHECK(CanRasterSlowTileCheck(recorded_viewport_));
   return true;
 }