Test region decoding in skimage, plus fixes.

src/images/SkImageDecoder_libwebp.cpp

 /*
  * Copyright 2010, The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *     http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
@@ skipping 93 matching lines @@
     virtual ~SkWEBPImageDecoder() {
         SkSafeUnref(fInputStream);
     }
 
     virtual Format getFormat() const SK_OVERRIDE {
         return kWEBP_Format;
     }
 
 protected:
     virtual bool onBuildTileIndex(SkStream *stream, int *width, int *height) SK_OVERRIDE;
-    virtual bool onDecodeRegion(SkBitmap* bitmap, const SkIRect& rect) SK_OVERRIDE;
+    virtual bool onDecodeSubset(SkBitmap* bitmap, const SkIRect& rect) SK_OVERRIDE;
     virtual bool onDecode(SkStream* stream, SkBitmap* bm, Mode) SK_OVERRIDE;
 
 private:
     bool setDecodeConfig(SkBitmap* decodedBitmap, int width, int height);
     SkStream* fInputStream;
     int fOrigWidth;
     int fOrigHeight;
     int fHasAlpha;
 
     typedef SkImageDecoder INHERITED;
@@ skipping 189 matching lines @@
     return true;
 }
 
 static bool is_config_compatible(const SkBitmap& bitmap) {
     SkBitmap::Config config = bitmap.config();
     return config == SkBitmap::kARGB_4444_Config ||
            config == SkBitmap::kRGB_565_Config ||
            config == SkBitmap::kARGB_8888_Config;
 }
 
-bool SkWEBPImageDecoder::onDecodeRegion(SkBitmap* decodedBitmap,
+bool SkWEBPImageDecoder::onDecodeSubset(SkBitmap* decodedBitmap,
                                         const SkIRect& region) {
     SkIRect rect = SkIRect::MakeWH(fOrigWidth, fOrigHeight);
 
     if (!rect.intersect(region)) {
         // If the requested region is entirely outsides the image, return false
         return false;
     }
 
     const int sampleSize = this->getSampleSize();
     SkScaledBitmapSampler sampler(rect.width(), rect.height(), sampleSize);
@@ skipping 260 matching lines @@
     return SkImageDecoder::kUnknown_Format;
 }
 
 static SkImageEncoder* sk_libwebp_efactory(SkImageEncoder::Type t) {
       return (SkImageEncoder::kWEBP_Type == t) ? SkNEW(SkWEBPImageEncoder) : NULL;
 }
 
 static SkTRegistry<SkImageDecoder*, SkStream*> gDReg(sk_libwebp_dfactory);
 static SkTRegistry<SkImageDecoder::Format, SkStream*> gFormatReg(get_format_webp);
 static SkTRegistry<SkImageEncoder*, SkImageEncoder::Type> gEReg(sk_libwebp_efactory);