Make SkPicture/SkImageGenerator default to SkCodec

include/core/SkPicture.h

Index: include/core/SkPicture.h
diff --git a/include/core/SkPicture.h b/include/core/SkPicture.h
index 720747e9a3232eeb9b07931b1ad1e939f489e511..ba9c5ff77a787c71fa420e4f956d6a2045d7a7cc 100644
--- a/include/core/SkPicture.h
+++ b/include/core/SkPicture.h
@@ -46,6 +46,11 @@ public:
      */
     typedef bool (*InstallPixelRefProc)(const void* src, size_t length, SkBitmap* dst);
 
+    // FIXME: Replace this with an interface that creates an SkImageGenerator.
+    // skbug.com/4883
+    // skbug.com/4290
+    static bool DefaultInstall(const void*, size_t, SkBitmap*);
+
     /**
      *  Recreate a picture that was serialized into a stream.
      *  @param SkStream Serialized picture data. Ownership is unchanged by this call.
@@ -54,8 +59,7 @@ public:
      *  @return A new SkPicture representing the serialized data, or NULL if the stream is
      *          invalid.
      */
-    static SkPicture* CreateFromStream(SkStream*,
-                                       InstallPixelRefProc proc = &SkImageDecoder::DecodeMemory);
+    static SkPicture* CreateFromStream(SkStream*, InstallPixelRefProc proc = &DefaultInstall);

[reed1, 2016/02/09 15:29:53]

Do we need to expose DefaultInstall() directly? i.e. do clients ever need to
actually call it directly? Could we instead:

SkPicture* CreateFromStream(SkStream*);    // we handle installing our private
default
SkPicture* CreateFromStream(SkStream*, InstallPixelRefProc proc);   // they must
give us a proc

[scroggo, 2016/02/09 16:12:17]

Done.

 
     /**
      *  Recreate a picture that was serialized into a buffer. If the creation requires bitmap