Reland: Remove DCHECK_IMPLIES/CHECK_IMPLIES.

cc/tiles/tile_manager_unittest.cc

 // Copyright 2013 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 "base/run_loop.h"
 #include "base/thread_task_runner_handle.h"
 #include "cc/playback/display_list_raster_source.h"
 #include "cc/playback/display_list_recording_source.h"
 #include "cc/raster/raster_buffer.h"
 #include "cc/resources/resource_pool.h"
@@ skipping 107 matching lines @@
     ActivateTree();
     SetupPendingTree(pending_raster_source);
   }
 
   void SetupPendingTree(scoped_refptr<DisplayListRasterSource> raster_source) {
     host_impl_.CreatePendingTree();
     LayerTreeImpl* pending_tree = host_impl_.pending_tree();
 
     // Steal from the recycled tree.
     scoped_ptr<LayerImpl> old_pending_root = pending_tree->DetachLayerTree();
-    DCHECK_IMPLIES(old_pending_root, old_pending_root->id() == id_);
+    DCHECK(!old_pending_root || old_pending_root->id() == id_);
 
     scoped_ptr<FakePictureLayerImpl> pending_layer;
     if (old_pending_root) {
       pending_layer.reset(
           static_cast<FakePictureLayerImpl*>(old_pending_root.release()));
       pending_layer->SetRasterSourceOnPending(raster_source, Region());
     } else {
       pending_layer = FakePictureLayerImpl::CreateWithRasterSource(
           pending_tree, id_, raster_source);
       pending_layer->SetDrawsContent(true);
@@ skipping 1662 matching lines @@
 }
 
 // Ensures that the tile manager does not attempt to reuse tiles when partial
 // raster is disabled.
 TEST_F(TileManagerTest, PartialRasterSuccessfullyDisabled) {
   RunPartialRasterCheck(host_impl_.Pass(), false /* partial_raster_enabled */);
 }
 
 }  // namespace
 }  // namespace cc