Why are we afraid of saveLayer() bounds?

src/core/SkRecordOpts.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkRecordOpts.h"
 
 #include "SkRecordPattern.h"
@@ skipping 72 matching lines @@
     // Run until they stop changing things.
     while (apply(&onlyDraws, record) || apply(&noDraws, record));
 }
 
 // For some SaveLayer-[drawing command]-Restore patterns, merge the SaveLayer's alpha into the
 // draw, and no-op the SaveLayer and Restore.
 struct SaveLayerDrawRestoreNooper {
     typedef Pattern3<Is<SaveLayer>, IsDraw, Is<Restore> > Pattern;
 
     bool onMatch(SkRecord* record, Pattern* pattern, unsigned begin, unsigned end) {
-        SaveLayer* saveLayer = pattern->first<SaveLayer>();
-        if (saveLayer->bounds != NULL) {
-            // SaveLayer with bounds is too tricky for us.
-            return false;
-        }
-
-        SkPaint* layerPaint = saveLayer->paint;
+        // A SaveLayer's bounds field is just a hint, so we should be free to ignore it.
+        SkPaint* layerPaint = pattern->first<SaveLayer>()->paint;
         if (NULL == layerPaint) {
             // There wasn't really any point to this SaveLayer at all.
             return KillSaveLayerAndRestore(record, begin);
         }
 
         SkPaint* drawPaint = pattern->second<SkPaint>();
         if (drawPaint == NULL) {
             // We can just give the draw the SaveLayer's paint.
             // TODO(mtklein): figure out how to do this clearly
             return false;
@@ skipping 45 matching lines @@
     }
     static bool IsOnlyAlpha(SkColor color) {
         return SK_ColorTRANSPARENT == SkColorSetA(color, SK_AlphaTRANSPARENT);
     }
 };
 void SkRecordNoopSaveLayerDrawRestores(SkRecord* record) {
     SaveLayerDrawRestoreNooper pass;
     apply(&pass, record);
 }