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

tools/render_pictures_main.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 "LazyDecodeBitmap.h"
 #include "CopyTilesRenderer.h"
 #include "SkBitmap.h"
@@ skipping 187 matching lines @@
     }
 
     renderer.setup();
     renderer.enableWrites();
 
     bool success = renderer.render(out);
     if (!success) {
         SkDebugf("Failed to render %s\n", inputFilename.c_str());
     }
 
-    if (FLAGS_preprocess) {
-        if (NULL != renderer.getCanvas()) {
-            renderer.getCanvas()->EXPERIMENTAL_purge(renderer.getPicture());
-        }
-    }
-
     renderer.end();
 
     SkDELETE(picture);
     return success;
 }
 
 static inline int getByte(uint32_t value, int index) {
     SkASSERT(0 <= index && index < 4);
     return (value >> (index * 8)) & 0xFF;
 }
@@ skipping 264 matching lines @@
         jsonSummary.writeToFile(FLAGS_writeJsonSummaryPath[0]);
     }
     return 0;
 }
 
 #if !defined SK_BUILD_FOR_IOS
 int main(int argc, char * const argv[]) {
     return tool_main(argc, (char**) argv);
 }
 #endif