Add auto purging for SkPicture-related Ganesh resources (esp. layers)

tools/PictureBenchmark.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Timer.h"
 #include "PictureBenchmark.h"
 #include "SkCanvas.h"
@@ skipping 63 matching lines @@
 
     if (fPreprocess) {
         if (NULL != fRenderer->getCanvas()) {
             fRenderer->getCanvas()->EXPERIMENTAL_optimize(pict);
         }
     }
 
     fRenderer->render(NULL);
     fRenderer->resetState(true);   // flush, swapBuffers and Finish
 
-    if (fPreprocess) {
-        if (NULL != fRenderer->getCanvas()) {
-            fRenderer->getCanvas()->EXPERIMENTAL_purge(pict);
-        }
-    }
-
     if (fPurgeDecodedTex) {
         fRenderer->purgeTextures();
     }
 
     bool usingGpu = false;
 #if SK_SUPPORT_GPU
     usingGpu = fRenderer->isUsingGpuDevice();
 #endif
 
     uint32_t timerTypes = fTimerTypes;
@@ skipping 113 matching lines @@
                 fRenderer->setup();
 
                 perRunTimer->start();
                 fRenderer->render(NULL);
                 perRunTimer->truncatedEnd();
                 fRenderer->resetState(false);   // flush & swapBuffers, but don't Finish
                 perRunTimer->end();
 
                 SkAssertResult(perRunTimerData.appendTimes(perRunTimer.get()));
 
-                if (fPreprocess) {
-                    if (NULL != fRenderer->getCanvas()) {
-                        fRenderer->getCanvas()->EXPERIMENTAL_purge(pict);
-                    }
-                }
-
                 if (fPurgeDecodedTex) {
                     fRenderer->purgeTextures();
                 }
             }
             longRunningTimer->truncatedEnd();
             fRenderer->resetState(true);        // flush, swapBuffers and Finish
             longRunningTimer->end();
             SkAssertResult(longRunningTimerData.appendTimes(longRunningTimer.get()));
         }
 
@@ skipping 17 matching lines @@
                 fTimerResult,
                 timerTypes,
                 numInnerLoops);
 #endif
     }
 
     fRenderer->end();
 }
 
 }