cc: Inflate invalidation in each picture list

cc/resources/picture_pile.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/resources/picture_pile.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "cc/base/region.h"
@@ skipping 28 matching lines @@
     RenderingStats* stats) {
   background_color_ = background_color;
 
   gfx::Rect interest_rect = visible_layer_rect;
   interest_rect.Inset(
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord,
       -kPixelDistanceToRecord);
   for (Region::Iterator i(invalidation); i.has_rect(); i.next()) {
-    // Inflate all recordings from invalidations with a margin so that when
-    // scaled down to at least min_contents_scale, any final pixel touched by an
-    // invalidation can be fully rasterized by this picture.
-    gfx::Rect inflated_invalidation = i.rect();
-    inflated_invalidation.Inset(
-        -buffer_pixels(),
-        -buffer_pixels(),
-        -buffer_pixels(),
-        -buffer_pixels());
+    gfx::Rect invalidation = i.rect();
     // Split this inflated invalidation across tile boundaries and apply it
     // to all tiles that it touches.
-    for (TilingData::Iterator iter(&tiling_, inflated_invalidation);
+    for (TilingData::Iterator iter(&tiling_, invalidation);
          iter; ++iter) {
       gfx::Rect tile =
           tiling_.TileBoundsWithBorder(iter.index_x(), iter.index_y());
       if (!tile.Intersects(interest_rect)) {
         // This invalidation touches a tile outside the interest rect, so
         // just remove the entire picture list.
         picture_list_map_.erase(iter.index());
         continue;
       }
 
-      gfx::Rect tile_invalidation =
-          gfx::IntersectRects(inflated_invalidation, tile);
+      gfx::Rect tile_invalidation = gfx::IntersectRects(invalidation, tile);
       if (tile_invalidation.IsEmpty())
         continue;
       PictureListMap::iterator find = picture_list_map_.find(iter.index());
       if (find == picture_list_map_.end())
         continue;
       PictureList& pic_list = find->second;
       // Leave empty pic_lists empty in case there are multiple invalidations.
-      if (!pic_list.empty())
+      if (!pic_list.empty()) {
+        // Inflate all recordings from invalidations with a margin so that when
+        // scaled down to at least min_contents_scale, any final pixel touched
+        // by an invalidation can be fully rasterized by this picture.
+        tile_invalidation.Inset(-buffer_pixels(), -buffer_pixels());
+
+        DCHECK_GE(tile_invalidation.width(), buffer_pixels() * 2 + 1);
+        DCHECK_GE(tile_invalidation.height(), buffer_pixels() * 2 + 1);
+
         InvalidateRect(pic_list, tile_invalidation);
+      }
     }
   }
 
   // Walk through all pictures in the rect of interest and record.
   for (TilingData::Iterator iter(&tiling_, interest_rect); iter; ++iter) {
     // Create a picture in this list if it doesn't exist.
     PictureList& pic_list = picture_list_map_[iter.index()];
     if (pic_list.empty()) {
       // Inflate the base picture with a margin, similar to invalidations, so
       // that when scaled down to at least min_contents_scale, the enclosed
@@ skipping 60 matching lines @@
 
   FullyContainedPredicate pred(picture_rect);
   picture_list.erase(std::remove_if(picture_list.begin(),
                                     picture_list.end(),
                                     pred),
                      picture_list.end());
   picture_list.push_back(Picture::Create(picture_rect));
 }
 
 }  // namespace cc