cc: Don't swap PictureLayerTilingSet on activate.

cc/resources/picture_layer_tiling_unittest.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_layer_tiling.h"
 
 #include <limits>
 #include <set>
 
 #include "cc/base/math_util.h"
@@ skipping 1351 matching lines @@
                           1.f,                      // current contents scale
                           1.0);                     // current frame time
 
   // The active tiling has tiles now.
   VerifyTiles(active_set->tiling_at(0), 1.f, gfx::Rect(layer_bounds),
               base::Bind(&TileExists, true));
 
   // Add the same tilings to the pending set.
   auto pending_set = PictureLayerTilingSet::Create(&client_);
   Region invalidation;
-  pending_set->SyncTilings(*active_set, layer_bounds, invalidation, 0.f,
-                           client_.raster_source());
+  pending_set->SyncTilingsForTesting(*active_set, layer_bounds, invalidation,
+                                     0.f, client_.raster_source());
 
   // The pending tiling starts with no tiles.
   VerifyTiles(pending_set->tiling_at(0), 1.f, gfx::Rect(layer_bounds),
               base::Bind(&TileExists, false));
 
   // ComputeTilePriorityRects on the pending tiling at the same frame time. The
   // pending tiling should get tiles.
   UpdateAllTilePriorities(pending_set.get(),
                           gfx::Rect(layer_bounds),  // visible content rect
                           1.f,                      // current contents scale
@@ skipping 671 matching lines @@
                                             invalidation, gfx::Size(250, 150));
 
   // Tile size in the tiling should be resized to 250x200.
   EXPECT_EQ(250, tiling_->TilingDataForTesting().max_texture_size().width());
   EXPECT_EQ(200, tiling_->TilingDataForTesting().max_texture_size().height());
   EXPECT_EQ(0u, tiling_->AllRefTilesForTesting().size());
 }
 
 }  // namespace
 }  // namespace cc