Add the method isOpaque() to SkImage

src/image/SkImage_Gpu.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkImage_Base.h"
 #include "SkImagePriv.h"
 #include "SkBitmap.h"
@@ skipping 13 matching lines @@
     virtual void onDrawRectToRect(SkCanvas*, const SkRect* src, const SkRect& dst,
                                   const SkPaint*) const SK_OVERRIDE;
     virtual GrTexture* onGetTexture() const SK_OVERRIDE;
     virtual bool getROPixels(SkBitmap*) const SK_OVERRIDE;
 
     GrTexture* getTexture() const { return fBitmap.getTexture(); }
 
     virtual SkShader* onNewShader(SkShader::TileMode,
                                   SkShader::TileMode,
                                   const SkMatrix* localMatrix) const SK_OVERRIDE;
+
+    virtual bool isOpaque() const SK_OVERRIDE;
+
 private:
     SkBitmap    fBitmap;
 
     typedef SkImage_Base INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 SkImage_Gpu::SkImage_Gpu(const SkBitmap& bitmap)
     : INHERITED(bitmap.width(), bitmap.height())
@@ skipping 21 matching lines @@
 }
 
 GrTexture* SkImage_Gpu::onGetTexture() const {
     return fBitmap.getTexture();
 }
 
 bool SkImage_Gpu::getROPixels(SkBitmap* dst) const {
     return fBitmap.copyTo(dst, kN32_SkColorType);
 }
 
+bool SkImage_Gpu::isOpaque() const {
+    return fBitmap.isOpaque();
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 
 SkImage* SkImage::NewTexture(const SkBitmap& bitmap) {
     if (NULL == bitmap.getTexture()) {
         return NULL;
     }
 
     return SkNEW_ARGS(SkImage_Gpu, (bitmap));
 }
 
 GrTexture* SkTextureImageGetTexture(SkImage* image) {
     return ((SkImage_Gpu*)image)->getTexture();
 }