Implement support for expanding crop rects in image filters

src/effects/SkXfermodeImageFilter.cpp

 /*
  * Copyright 2013 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 "SkXfermodeImageFilter.h"
 #include "SkCanvas.h"
 #include "SkDevice.h"
@@ skipping 44 matching lines @@
         !backgroundInput->filterImage(proxy, src, ctx, &background, &backgroundOffset)) {
         return false;
     }
     SkIPoint foregroundOffset = SkIPoint::Make(0, 0);
     if (foregroundInput &&
         !foregroundInput->filterImage(proxy, src, ctx, &foreground, &foregroundOffset)) {
         return false;
     }
 
     SkIRect bounds, foregroundBounds;
-    background.getBounds(&bounds);
-    bounds.offset(backgroundOffset);
-    foreground.getBounds(&foregroundBounds);
-    foregroundBounds.offset(foregroundOffset);
-    bounds.join(foregroundBounds);
-    if (!applyCropRect(&bounds, ctx.ctm())) {
+    if (!applyCropRect(ctx, foreground, foregroundOffset, &foregroundBounds)) {
         return false;
     }
+    if (!applyCropRect(ctx, background, backgroundOffset, &bounds)) {
+        return false;
+    }
+    bounds.join(foregroundBounds);
 
     SkAutoTUnref<SkBaseDevice> device(proxy->createDevice(bounds.width(), bounds.height()));
     if (NULL == device.get()) {
         return false;
     }
     SkCanvas canvas(device);
     canvas.translate(SkIntToScalar(-bounds.left()), SkIntToScalar(-bounds.top()));
     SkPaint paint;
     paint.setXfermodeMode(SkXfermode::kSrc_Mode);
     canvas.drawBitmap(background, SkIntToScalar(backgroundOffset.fX),
@@ skipping 74 matching lines @@
         foregroundPaint.addColorTextureEffect(foregroundTex, foregroundMatrix);
         context->drawRect(foregroundPaint, srcRect);
     }
     offset->fX = backgroundOffset.fX;
     offset->fY = backgroundOffset.fY;
     WrapTexture(dst, src.width(), src.height(), result);
     return true;
 }
 
 #endif