Revert of Remove DCHECK_IMPLIES/CHECK_IMPLIES.

cc/tiles/tile_manager.cc

Index: cc/tiles/tile_manager.cc
diff --git a/cc/tiles/tile_manager.cc b/cc/tiles/tile_manager.cc
index eccf3f0bf17a551d53a9a5ccf37cb2478da23596..56e6971a8b746abed8966fadd810f73c9b59a854 100644
--- a/cc/tiles/tile_manager.cc
+++ b/cc/tiles/tile_manager.cc
@@ -521,8 +521,8 @@
 
     tile->scheduled_priority_ = schedule_priority++;
 
-    DCHECK(tile->draw_info().mode() == TileDrawInfo::OOM_MODE ||
-           !tile->draw_info().IsReadyToDraw());
+    DCHECK_IMPLIES(tile->draw_info().mode() != TileDrawInfo::OOM_MODE,
+                   !tile->draw_info().IsReadyToDraw());
 
     // If the tile already has a raster_task, then the memory used by it is
     // already accounted for in memory_usage. Otherwise, we'll have to acquire
@@ -795,8 +795,8 @@
       client_->BuildRasterQueue(global_state_.tree_priority, type));
   for (; !all_queue->IsEmpty(); all_queue->Pop()) {
     Tile* tile = all_queue->Top().tile();
-    DCHECK(!tile->required_for_activation() ||
-           tile->draw_info().IsReadyToDraw());
+    DCHECK_IMPLIES(tile->required_for_activation(),
+                   tile->draw_info().IsReadyToDraw());
   }
 #endif
   return true;