Remove obsolete RECORD_WITH_SK_NULL_CANVAS recording mode.

cc/playback/recording_source.h

 // 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.
 
 #ifndef CC_PLAYBACK_RECORDING_SOURCE_H_
 #define CC_PLAYBACK_RECORDING_SOURCE_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 13 matching lines @@
 }  // namespace proto
 
 class ClientPictureCache;
 class ContentLayerClient;
 class DisplayItemList;
 class RasterSource;
 class Region;
 
 class CC_EXPORT RecordingSource {
  public:
-  // TODO(schenney) Remove RECORD_WITH_SK_NULL_CANVAS when we no longer
-  // support a non-Slimming Paint path.
   enum RecordingMode {
     RECORD_NORMALLY,
-    RECORD_WITH_SK_NULL_CANVAS,
     RECORD_WITH_PAINTING_DISABLED,
     RECORD_WITH_CACHING_DISABLED,
     RECORD_WITH_CONSTRUCTION_DISABLED,
     RECORD_WITH_SUBSEQUENCE_CACHING_DISABLED,
     RECORDING_MODE_COUNT,  // Must be the last entry.
   };
 
   RecordingSource();
   virtual ~RecordingSource();
 
@@ skipping 47 matching lines @@
   void DetermineIfSolidColor();
 
   InvalidationRegion invalidation_;
 
   DISALLOW_COPY_AND_ASSIGN(RecordingSource);
 };
 
 }  // namespace cc
 
 #endif  // CC_PLAYBACK_RECORDING_SOURCE_H_