writepixels needs to bump genID

src/core/SkCanvas.cpp

 /*
  * Copyright 2008 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 "SkCanvas.h"
 #include "SkBitmapDevice.h"
@@ skipping 735 matching lines @@
     // if x or y are negative, then we have to adjust pixels
     if (x > 0) {
         x = 0;
     }
     if (y > 0) {
         y = 0;
     }
     // here x,y are either 0 or negative
     pixels = ((const char*)pixels - y * rowBytes - x * info.bytesPerPixel());
 
+    // Tell our owning surface to bump its generation ID
+    this->predrawNotify();
+
     // The device can assert that the requested area is always contained in its bounds
     return device->writePixels(info, pixels, rowBytes, target.x(), target.y());
 }
 
 SkCanvas* SkCanvas::canvasForDrawIter() {
     return this;
 }
 
 //////////////////////////////////////////////////////////////////////////////
 
@@ skipping 1816 matching lines @@
     if (!supported_for_raster_canvas(info)) {
         return NULL;
     }
 
     SkBitmap bitmap;
     if (!bitmap.installPixels(info, pixels, rowBytes)) {
         return NULL;
     }
     return SkNEW_ARGS(SkCanvas, (bitmap));
 }