make info real in SkPixelRef, and add bitmap::asImageInfo

include/core/SkBitmap.h

 
 /*
  * Copyright 2006 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.
  */
 
 
 #ifndef SkBitmap_DEFINED
@@ skipping 232 matching lines @@
     */
     bool setConfig(Config, int width, int height, size_t rowBytes, SkAlphaType);
 
     bool setConfig(Config config, int width, int height, size_t rowBytes = 0) {
         return this->setConfig(config, width, height, rowBytes,
                                kPremul_SkAlphaType);
     }
 
     bool setConfig(const SkImageInfo& info, size_t rowBytes = 0);
 
+    /**
+     *  If the bitmap's config can be represented as SkImageInfo, return true,
+     *  and if info is not-null, set it to the bitmap's info. If it cannot be
+     *  represented as SkImageInfo, return false and ignore the info parameter.
+     */
+    bool asImageInfo(SkImageInfo* info) const;
+
     /** Use this to assign a new pixel address for an existing bitmap. This
         will automatically release any pixelref previously installed. Only call
         this if you are handling ownership/lifetime of the pixel memory.
 
         If the bitmap retains a reference to the colortable (assuming it is
         not null) it will take care of incrementing the reference count.
 
         @param pixels   Address for the pixels, managed by the caller.
         @param ctable   ColorTable (or null) that matches the specified pixels
     */
@@ skipping 535 matching lines @@
 
 inline SkPMColor SkBitmap::getIndex8Color(int x, int y) const {
     SkASSERT(fPixels);
     SkASSERT(fConfig == kIndex8_Config);
     SkASSERT((unsigned)x < fWidth && (unsigned)y < fHeight);
     SkASSERT(fColorTable);
     return (*fColorTable)[*((const uint8_t*)fPixels + y * fRowBytes + x)];
 }
 
 #endif