Revert of cc: Replace recorded region with direct map lookup

cc/resources/picture_pile_base.cc

Index: cc/resources/picture_pile_base.cc
diff --git a/cc/resources/picture_pile_base.cc b/cc/resources/picture_pile_base.cc
index 4f04fddec7108b1de02d05d0c68a38079efd4972..2c87f596c800b708d2e6f3218397b420f1942a31 100644
--- a/cc/resources/picture_pile_base.cc
+++ b/cc/resources/picture_pile_base.cc
@@ -44,8 +44,7 @@
       slow_down_raster_scale_factor_for_debug_(0),
       contents_opaque_(false),
       show_debug_picture_borders_(false),
-      clear_canvas_with_debug_color_(kDefaultClearCanvasSetting),
-      has_any_recordings_(false) {
+      clear_canvas_with_debug_color_(kDefaultClearCanvasSetting) {
   tiling_.SetMaxTextureSize(gfx::Size(kBasePictureSize, kBasePictureSize));
   tile_grid_info_.fTileInterval.setEmpty();
   tile_grid_info_.fMargin.setEmpty();
@@ -55,7 +54,7 @@
 PicturePileBase::PicturePileBase(const PicturePileBase* other)
     : picture_map_(other->picture_map_),
       tiling_(other->tiling_),
-      recorded_viewport_(other->recorded_viewport_),
+      recorded_region_(other->recorded_region_),
       min_contents_scale_(other->min_contents_scale_),
       tile_grid_info_(other->tile_grid_info_),
       background_color_(other->background_color_),
@@ -63,13 +62,13 @@
           other->slow_down_raster_scale_factor_for_debug_),
       contents_opaque_(other->contents_opaque_),
       show_debug_picture_borders_(other->show_debug_picture_borders_),
-      clear_canvas_with_debug_color_(other->clear_canvas_with_debug_color_),
-      has_any_recordings_(other->has_any_recordings_) {}
-
-PicturePileBase::PicturePileBase(const PicturePileBase* other,
-                                 unsigned thread_index)
+      clear_canvas_with_debug_color_(other->clear_canvas_with_debug_color_) {
+}
+
+PicturePileBase::PicturePileBase(
+    const PicturePileBase* other, unsigned thread_index)
     : tiling_(other->tiling_),
-      recorded_viewport_(other->recorded_viewport_),
+      recorded_region_(other->recorded_region_),
       min_contents_scale_(other->min_contents_scale_),
       tile_grid_info_(other->tile_grid_info_),
       background_color_(other->background_color_),
@@ -77,8 +76,7 @@
           other->slow_down_raster_scale_factor_for_debug_),
       contents_opaque_(other->contents_opaque_),
       show_debug_picture_borders_(other->show_debug_picture_borders_),
-      clear_canvas_with_debug_color_(other->clear_canvas_with_debug_color_),
-      has_any_recordings_(other->has_any_recordings_) {
+      clear_canvas_with_debug_color_(other->clear_canvas_with_debug_color_) {
   for (PictureMap::const_iterator it = other->picture_map_.begin();
        it != other->picture_map_.end();
        ++it) {
@@ -95,8 +93,6 @@
 
   gfx::Size old_size = size();
   tiling_.SetTotalSize(new_size);
-
-  has_any_recordings_ = false;
 
   // Find all tiles that contain any pixels outside the new size.
   std::vector<PictureMapKey> to_erase;
@@ -108,18 +104,13 @@
        it != picture_map_.end();
        ++it) {
     const PictureMapKey& key = it->first;
-    if (key.first < min_toss_x && key.second < min_toss_y) {
-      has_any_recordings_ |= !!it->second.GetPicture();
+    if (key.first < min_toss_x && key.second < min_toss_y)
       continue;
-    }
     to_erase.push_back(key);
   }
 
   for (size_t i = 0; i < to_erase.size(); ++i)
     picture_map_.erase(to_erase[i]);
-
-  // Don't waste time in Resize figuring out what these hints should be.
-  recorded_viewport_ = gfx::Rect();
 }
 
 void PicturePileBase::SetMinContentsScale(float min_contents_scale) {
@@ -175,6 +166,18 @@
   picture_map_.clear();
 }
 
+void PicturePileBase::UpdateRecordedRegion() {
+  recorded_region_.Clear();
+  for (PictureMap::const_iterator it = picture_map_.begin();
+       it != picture_map_.end();
+       ++it) {
+    if (it->second.GetPicture()) {
+      const PictureMapKey& key = it->first;
+      recorded_region_.Union(tile_bounds(key.first, key.second));
+    }
+  }
+}
+
 bool PicturePileBase::HasRecordingAt(int x, int y) {
   PictureMap::const_iterator found = picture_map_.find(PictureMapKey(x, y));
   if (found == picture_map_.end())
@@ -189,28 +192,7 @@
   gfx::Rect layer_rect = gfx::ScaleToEnclosingRect(
       content_rect, 1.f / contents_scale);
   layer_rect.Intersect(gfx::Rect(tiling_.total_size()));
-
-  // Common case inside of viewport to avoid the slower map lookups.
-  if (recorded_viewport_.Contains(layer_rect)) {
-    // Sanity check that there are no false positives in recorded_viewport_.
-    DCHECK(CanRasterSlowTileCheck(layer_rect));
-    return true;
-  }
-
-  return CanRasterSlowTileCheck(layer_rect);
-}
-
-bool PicturePileBase::CanRasterSlowTileCheck(
-    const gfx::Rect& layer_rect) const {
-  for (TilingData::Iterator tile_iter(&tiling_, layer_rect); tile_iter;
-       ++tile_iter) {
-    PictureMap::const_iterator map_iter = picture_map_.find(tile_iter.index());
-    if (map_iter == picture_map_.end())
-      return false;
-    if (!map_iter->second.GetPicture())
-      return false;
-  }
-  return true;
+  return recorded_region_.Contains(layer_rect);
 }
 
 gfx::Rect PicturePileBase::PaddedRect(const PictureMapKey& key) {