Reland: Remove DCHECK_IMPLIES/CHECK_IMPLIES.

cc/tiles/picture_layer_tiling_set.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/tiles/picture_layer_tiling_set.h"
 
 #include <limits>
 #include <set>
 #include <vector>
 
@@ skipping 122 matching lines @@
 void PictureLayerTilingSet::UpdateTilingsToCurrentRasterSourceForCommit(
     scoped_refptr<DisplayListRasterSource> raster_source,
     const Region& layer_invalidation,
     float minimum_contents_scale,
     float maximum_contents_scale) {
   RemoveTilingsBelowScale(minimum_contents_scale);
   RemoveTilingsAboveScale(maximum_contents_scale);
 
   // Invalidate tiles and update them to the new raster source.
   for (PictureLayerTiling* tiling : tilings_) {
-    DCHECK_IMPLIES(tree_ == PENDING_TREE, !tiling->has_tiles());
+    DCHECK(tree_ != PENDING_TREE || !tiling->has_tiles());
     tiling->SetRasterSourceAndResize(raster_source);
 
     // We can commit on either active or pending trees, but only active one can
     // have tiles at this point.
     if (tree_ == ACTIVE_TREE)
       tiling->Invalidate(layer_invalidation);
 
     // This is needed for cases where the live tiles rect didn't change but
     // recordings exist in the raster source that did not exist on the last
     // raster source.
@@ skipping 421 matching lines @@
     case LOWER_THAN_LOW_RES:
       range = TilingRange(low_res_range.end, tilings_size);
       break;
   }
 
   DCHECK_LE(range.start, range.end);
   return range;
 }
 
 }  // namespace cc