Update from https://crrev.com/317530

cc/resources/tiling_set_eviction_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 <utility>
 
 #include "cc/resources/tiling_set_eviction_queue.h"
 
 namespace cc {
 
@@ skipping 312 matching lines @@
 
   switch (tree_priority_) {
     case SMOOTHNESS_TAKES_PRIORITY:
       DCHECK_EQ(ACTIVE_TREE, tree_);
       return false;
     case NEW_CONTENT_TAKES_PRIORITY:
       DCHECK_EQ(PENDING_TREE, tree_);
       return false;
     case SAME_PRIORITY_FOR_BOTH_TREES:
       break;
-    case NUM_TREE_PRIORITIES:
-      NOTREACHED();
-      break;
   }
 
   // The priority for tile priority of a shared tile will be a combined
   // priority thus return shared tiles from a higher priority tree as
   // it is out of order for a lower priority tree.
   WhichTree twin_tree = tree_ == ACTIVE_TREE ? PENDING_TREE : ACTIVE_TREE;
   const TilePriority& priority = tile->priority(tree_);
   const TilePriority& twin_priority = tile->priority(twin_tree);
   if (priority.priority_bin != twin_priority.priority_bin)
     return priority.priority_bin > twin_priority.priority_bin;
@@ skipping 38 matching lines @@
           tiling_set_->client()->GetPendingOrActiveTwinTiling(tiling);
       if (pending_tiling && pending_tiling->resolution() == HIGH_RESOLUTION)
         return i;
     }
   }
 
   return num_tilings;
 }
 
 }  // namespace cc