cc: Implement geometry-based tile eviction

cc/resources/eviction_tile_priority_queue.cc

 // Copyright 2014 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/eviction_tile_priority_queue.h"
 
 namespace cc {
 
 namespace {
 
@@ skipping 195 matching lines @@
   const Tile* active_tile = *active_iterator;
   const Tile* pending_tile = *pending_iterator;
   if (active_tile == pending_tile)
     return ACTIVE_TREE;
 
   const TilePriority& active_priority =
       active_tile->priority_for_tree_priority(tree_priority);
   const TilePriority& pending_priority =
       pending_tile->priority_for_tree_priority(tree_priority);
 
+  if (active_priority.priority_bin == pending_priority.priority_bin) {

[vmpstr, 2014/11/19 16:47:58]

*

+    if (active_tile->required_for_activation()) {
+      if (!pending_tile->required_for_activation())
+        return PENDING_TREE;
+    } else {
+      if (pending_tile->required_for_activation())
+        return ACTIVE_TREE;
+    }
+  }
+
   if (pending_priority.IsHigherPriorityThan(active_priority))
     return ACTIVE_TREE;
   return PENDING_TREE;
 }
 
 }  // namespace cc