Add a src rect to drawImageLattice() API

src/pipe/SkPipeCanvas.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPathEffect.h"
 #include "SkColorFilter.h"
 #include "SkDrawLooper.h"
@@ skipping 564 matching lines @@
     }
     // Often these divs will be small (8 or 16 bits). Consider sniffing that and writing a flag
     // so we can store them smaller.
     writer.write(lattice.fXDivs, lattice.fXCount * sizeof(int32_t));
     writer.write(lattice.fYDivs, lattice.fYCount * sizeof(int32_t));
     if (lattice.fFlags) {
         int32_t count = (lattice.fXCount + 1) * (lattice.fYCount + 1);
         SkASSERT(count > 0);
         write_pad(&writer, lattice.fFlags, count);
     }
+    SkASSERT(lattice.fBounds);
+    writer.write(&lattice.fBounds, sizeof(*lattice.fBounds));
     writer.write(&dst, sizeof(dst));
     if (paint) {
         write_paint(writer, *paint, kImage_PaintUsage);
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 void SkPipeCanvas::onDrawText(const void* text, size_t byteLength, SkScalar x, SkScalar y,
                               const SkPaint& paint) {
@@ skipping 472 matching lines @@
     fImpl->fDeduper.setStream(stream);
     fImpl->fDeduper.setCanvas(fImpl->fCanvas.get());
     return fImpl->fCanvas.get();
 }
 
 void SkPipeSerializer::endWrite() {
     fImpl->fCanvas->restoreToCount(1);
     fImpl->fCanvas.reset(nullptr);
     fImpl->fDeduper.setCanvas(nullptr);
 }