add installPixels

include/core/SkBitmap.h

Index: include/core/SkBitmap.h
diff --git a/include/core/SkBitmap.h b/include/core/SkBitmap.h
index f53a0a7e45a4d98a7eed2104027794cd33029dfc..4732591e9246524ad58a8c9dc3f7fbd3d7f31ecd 100644
--- a/include/core/SkBitmap.h
+++ b/include/core/SkBitmap.h
@@ -248,7 +248,25 @@ public:
     }
 
     bool setConfig(const SkImageInfo& info, size_t rowBytes = 0);
-
+    
+    /**
+     *  Allocate a pixelref to match the specified image info, using the default
+     *  allocator, computing a minimum rowBytes based on info.
+     *  On failure, the bitmap will be set to empty and return false.
+     */
+    bool allocPixels(const SkImageInfo&, SkColorTable* ctable = NULL);

[scroggo, 2014/01/23 21:53:02]

I assume these are to replace the existing setConfig + allocPixels. Does it make
sense to continue to allow the caller to specify how the pixels are allocated?
Or will they just then be forced to call installPixels?

Currently, Android passes an SkBitmap::Allocator to the image decoders. Their
special Allocator provides a Java allocation of memory that they can reuse for
future bitmaps. How can we continue to support this pattern? Perhaps their
Allocator can call installPixels?

[hal.canary, 2014/01/23 22:05:24]

Why not:

    bool allocPixels(const SkImageInfo&, 
                     Allocator*,
                     SkColorTable*);

[reed1, 2014/01/24 14:54:48]

Done.

+    
+    /**
+     *  Install a pixelref that wraps the specified pixels and rowBytes, and
+     *  optional ReleaseProc and context. When the pixels are no longer
+     *  referenced, if ReleaseProc is not null, it will be called with the
+     *  pixels and context as parameters.
+     *  On failure, the bitmap will be set to empty and return false.
+     */
+    bool installPixels(const SkImageInfo&, void* pixels, size_t rowBytes,
+                       void (*ReleaseProc)(void* addr, void* context),
+                       void* context);
+    
     /**
      *  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