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

src/core/SkPicture.cpp

 
 /*
  * Copyright 2007 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkPictureFlat.h"
@@ skipping 126 matching lines @@
 
 // Create an SkPictureData-backed SkPicture from an SkRecord.
 // This for compatibility with serialization code only.  This is not cheap.
 static SkPicture* backport(const SkRecord& src, int width, int height) {
     SkPictureRecorder recorder;
     SkRecordDraw(src, recorder.beginRecording(width, height));
     return recorder.endRecording();
 }
 
 // fRecord OK
-SkPicture::~SkPicture() {}
+SkPicture::~SkPicture() {
+    this->callDeletionListeners();
+}
 
 #ifdef SK_SUPPORT_LEGACY_PICTURE_CLONE
 // fRecord TODO, fix by deleting this method
 SkPicture* SkPicture::clone() const {
 
     SkAutoTDelete<SkPictureData> newData;
 
     if (fData.get()) {
         SkPictCopyInfo copyInfo;
 
@@ skipping 327 matching lines @@
 }
 
 // fRecord OK
 SkPicture::SkPicture(int width, int height, SkRecord* record)
     : fWidth(width)
     , fHeight(height)
     , fRecord(record)
     , fRecordWillPlayBackBitmaps(SkRecordWillPlaybackBitmaps(*record)) {
     this->needsNewGenID();
 }
+
+// Note that we are assuming that this entry point will only be called from
+// one thread. Currently the only client of this method is 
+// SkGpuDevice::EXPERIMENTAL_optimize which should be only called from a single
+// thread.
+void SkPicture::addDeletionListener(DeletionListener* listener) const {
+    SkASSERT(NULL != listener);
+
+    *fDeletionListeners.append() = SkRef(listener);
+}
+
+void SkPicture::callDeletionListeners() {
+    for (int i = 0; i < fDeletionListeners.count(); ++i) {
+        fDeletionListeners[i]->onDeletion(this->uniqueID());
+    }
+
+    fDeletionListeners.unrefAll();
+}