diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/lazy/SkDiscardablePixelRef.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/lazy/SkDiscardablePixelRef.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,99 @@
+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkDiscardablePixelRef.h"
+#include "SkDiscardableMemory.h"
+#include "SkImageGenerator.h"
+
+SkDiscardablePixelRef::SkDiscardablePixelRef(const SkImageInfo& info,
+                                             SkImageGenerator* generator,
+                                             size_t rowBytes,
+                                             SkDiscardableMemory::Factory* fact)
+    : INHERITED(info)
+    , fGenerator(generator)
+    , fDMFactory(fact)
+    , fRowBytes(rowBytes)
+    , fDiscardableMemory(NULL)
+{
+    SkASSERT(fGenerator != NULL);
+    SkASSERT(fRowBytes > 0);
+    // The SkImageGenerator contract requires fGenerator to always
+    // decode the same image on each call to getPixels().
+    this->setImmutable();
+    SkSafeRef(fDMFactory);
+}
+
+SkDiscardablePixelRef::~SkDiscardablePixelRef() {
+    if (this->isLocked()) {
+        fDiscardableMemory->unlock();
+    }
+    SkDELETE(fDiscardableMemory);
+    SkSafeUnref(fDMFactory);
+    SkDELETE(fGenerator);
+}
+
+bool SkDiscardablePixelRef::onNewLockPixels(LockRec* rec) {
+    if (fDiscardableMemory != NULL) {
+        if (fDiscardableMemory->lock()) {
+            rec->fPixels = fDiscardableMemory->data();
+            rec->fColorTable = NULL;
+            rec->fRowBytes = fRowBytes;
+            return true;
+        }
+        SkDELETE(fDiscardableMemory);
+        fDiscardableMemory = NULL;
+    }
+
+    const size_t size = this->info().getSafeSize(fRowBytes);
+
+    if (fDMFactory != NULL) {
+        fDiscardableMemory = fDMFactory->create(size);
+    } else {
+        fDiscardableMemory = SkDiscardableMemory::Create(size);
+    }
+    if (NULL == fDiscardableMemory) {
+        return false;  // Memory allocation failed.
+    }
+
+    void* pixels = fDiscardableMemory->data();
+    if (!fGenerator->getPixels(this->info(), pixels, fRowBytes)) {
+        fDiscardableMemory->unlock();
+        SkDELETE(fDiscardableMemory);
+        fDiscardableMemory = NULL;
+        return false;
+    }
+
+    rec->fPixels = pixels;
+    rec->fColorTable = NULL;
+    rec->fRowBytes = fRowBytes;
+    return true;
+}
+
+void SkDiscardablePixelRef::onUnlockPixels() {
+    fDiscardableMemory->unlock();
+}
+
+bool SkInstallDiscardablePixelRef(SkImageGenerator* generator,
+                                  SkBitmap* dst,
+                                  SkDiscardableMemory::Factory* factory) {
+    SkImageInfo info;
+    SkAutoTDelete<SkImageGenerator> autoGenerator(generator);
+    if ((NULL == autoGenerator.get())
+        || (!autoGenerator->getInfo(&info))
+        || (!dst->setConfig(info, 0))) {
+        return false;
+    }
+    SkASSERT(dst->colorType() != kUnknown_SkColorType);
+    if (dst->empty()) {  // Use a normal pixelref.
+        return dst->allocPixels();
+    }
+    SkAutoTUnref<SkDiscardablePixelRef> ref(
+        SkNEW_ARGS(SkDiscardablePixelRef,
+                   (info, autoGenerator.detach(), dst->rowBytes(), factory)));
+    dst->setPixelRef(ref);
+    return true;
+}