Change clear() to respect the clip

src/core/SkBitmapDevice.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 "SkBitmapDevice.h"
 #include "SkConfig8888.h"
 #include "SkDeviceProperties.h"
@@ skipping 109 matching lines @@
         fBitmap.lockPixels();
     }
 }
 
 void SkBitmapDevice::unlockPixels() {
     if (fBitmap.lockPixelsAreWritable()) {
         fBitmap.unlockPixels();
     }
 }
 
-void SkBitmapDevice::clear(SkColor color) {
-    fBitmap.eraseColor(color);
-}
-
 const SkBitmap& SkBitmapDevice::onAccessBitmap() {
     return fBitmap;
 }
 
 void* SkBitmapDevice::onAccessPixels(SkImageInfo* info, size_t* rowBytes) {
     if (fBitmap.getPixels()) {
         *info = fBitmap.info();
         *rowBytes = fBitmap.rowBytes();
         return fBitmap.getPixels();
     }
@@ skipping 243 matching lines @@
         paint.getRasterizer() ||
         paint.getPathEffect() ||
         paint.isFakeBoldText() ||
         paint.getStyle() != SkPaint::kFill_Style ||
         !SkXfermode::IsMode(paint.getXfermode(), SkXfermode::kSrcOver_Mode))
     {
         return true;
     }
     return false;
 }