diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/image/SkSurface.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/image/SkSurface.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,127 @@
+/*
+ * 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 "SkSurface_Base.h"
+#include "SkImagePriv.h"
+#include "SkCanvas.h"
+
+///////////////////////////////////////////////////////////////////////////////
+
+SkSurface_Base::SkSurface_Base(int width, int height) : INHERITED(width, height) {
+    fCachedCanvas = NULL;
+    fCachedImage = NULL;
+}
+
+SkSurface_Base::SkSurface_Base(const SkImageInfo& info) : INHERITED(info) {
+    fCachedCanvas = NULL;
+    fCachedImage = NULL;
+}
+
+SkSurface_Base::~SkSurface_Base() {
+    // in case the canvas outsurvives us, we null the callback
+    if (fCachedCanvas) {
+        fCachedCanvas->setSurfaceBase(NULL);
+    }
+
+    SkSafeUnref(fCachedImage);
+    SkSafeUnref(fCachedCanvas);
+}
+
+void SkSurface_Base::onDraw(SkCanvas* canvas, SkScalar x, SkScalar y,
+                            const SkPaint* paint) {
+    SkImage* image = this->newImageSnapshot();
+    if (image) {
+        image->draw(canvas, x, y, paint);
+        image->unref();
+    }
+}
+
+void SkSurface_Base::aboutToDraw(ContentChangeMode mode) {
+    this->dirtyGenerationID();
+
+    if (NULL != fCachedCanvas) {
+        SkASSERT(fCachedCanvas->getSurfaceBase() == this || \
+                 NULL == fCachedCanvas->getSurfaceBase());
+        fCachedCanvas->setSurfaceBase(NULL);
+    }
+
+    if (NULL != fCachedImage) {
+        // the surface may need to fork its backend, if its sharing it with
+        // the cached image. Note: we only call if there is an outstanding owner
+        // on the image (besides us).
+        if (!fCachedImage->unique()) {
+            this->onCopyOnWrite(mode);
+        }
+
+        // regardless of copy-on-write, we must drop our cached image now, so
+        // that the next request will get our new contents.
+        fCachedImage->unref();
+        fCachedImage = NULL;
+    }
+}
+
+uint32_t SkSurface_Base::newGenerationID() {
+    this->installIntoCanvasForDirtyNotification();
+
+    static int32_t gID;
+    return sk_atomic_inc(&gID) + 1;
+}
+
+static SkSurface_Base* asSB(SkSurface* surface) {
+    return static_cast<SkSurface_Base*>(surface);
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+SkSurface::SkSurface(int width, int height) : fWidth(width), fHeight(height) {
+    SkASSERT(fWidth >= 0);
+    SkASSERT(fHeight >= 0);
+    fGenerationID = 0;
+}
+
+SkSurface::SkSurface(const SkImageInfo& info)
+    : fWidth(info.fWidth)
+    , fHeight(info.fHeight)
+{
+    SkASSERT(fWidth >= 0);
+    SkASSERT(fHeight >= 0);
+    fGenerationID = 0;
+}
+
+uint32_t SkSurface::generationID() {
+    if (0 == fGenerationID) {
+        fGenerationID = asSB(this)->newGenerationID();
+    }
+    return fGenerationID;
+}
+
+void SkSurface::notifyContentWillChange(ContentChangeMode mode) {
+    asSB(this)->aboutToDraw(mode);
+}
+
+SkCanvas* SkSurface::getCanvas() {
+    return asSB(this)->getCachedCanvas();
+}
+
+SkImage* SkSurface::newImageSnapshot() {
+    SkImage* image = asSB(this)->getCachedImage();
+    SkSafeRef(image);   // the caller will call unref() to balance this
+    return image;
+}
+
+SkSurface* SkSurface::newSurface(const SkImageInfo& info) {
+    return asSB(this)->onNewSurface(info);
+}
+
+void SkSurface::draw(SkCanvas* canvas, SkScalar x, SkScalar y,
+                     const SkPaint* paint) {
+    return asSB(this)->onDraw(canvas, x, y, paint);
+}
+
+const void* SkSurface::peekPixels(SkImageInfo* info, size_t* rowBytes) {
+    return this->getCanvas()->peekPixels(info, rowBytes);
+}