Make filters use SkImage instead of SkBitmap

src/effects/SkRectShaderImageFilter.cpp

 /*
  * 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 "SkRectShaderImageFilter.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
@@ skipping 32 matching lines @@
 void SkRectShaderImageFilter::flatten(SkWriteBuffer& buffer) const {
     this->INHERITED::flatten(buffer);
     buffer.writeFlattenable(fShader);
 }
 
 SkRectShaderImageFilter::~SkRectShaderImageFilter() {
     fShader->unref();
 }
 
 bool SkRectShaderImageFilter::onFilterImage(Proxy* proxy,
-                                            const SkBitmap& source,
+                                            const SkImage* source,
                                             const Context& ctx,
-                                            SkBitmap* result,
+                                            SkAutoTUnref<const SkImage>& result,
                                             SkIPoint* offset) const {
     SkIRect bounds;
     if (!this->applyCropRect(ctx, source, SkIPoint::Make(0, 0), &bounds)) {
         return false;
     }
 
     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(),
                                                           bounds.height()));
     if (NULL == device.get()) {
         return false;
     }
     SkCanvas canvas(device.get());
 
     SkPaint paint;
     SkMatrix matrix(ctx.ctm());
     matrix.postTranslate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
     SkSafeUnref(paint.setShader(SkShader::CreateLocalMatrixShader(fShader, matrix)));
 
     SkRect rect = SkRect::MakeWH(SkIntToScalar(bounds.width()), SkIntToScalar(bounds.height()));
     canvas.drawRect(rect, paint);
+    SkImage* image = device->newImageSnapshot();
+    if (NULL == image) {
+        return false;
+    }
+    result.reset(image);
 
-    *result = device.get()->accessBitmap(false);
     offset->fX = bounds.fLeft;
     offset->fY = bounds.fTop;
     return true;
 }
 
 #ifndef SK_IGNORE_TO_STRING
 void SkRectShaderImageFilter::toString(SkString* str) const {
     str->appendf("SkRectShaderImageFilter: (");
     str->append(")");
 }
 #endif