Make peekPixels() usable with raster surface snapshots

src/image/SkImagePriv.h

Index: src/image/SkImagePriv.h
diff --git a/src/image/SkImagePriv.h b/src/image/SkImagePriv.h
index afaf3f173619ef376afaada9946345dcf4d1f1d8..888f3b74a40d2b9aebe489d11e355be2d950d4e4 100644
--- a/src/image/SkImagePriv.h
+++ b/src/image/SkImagePriv.h
@@ -19,9 +19,11 @@ extern SkImage* SkNewImageFromPixelRef(const SkImageInfo&, SkPixelRef*,
 
 /**
  *  Examines the bitmap to decide if it can share the existing pixelRef, or
- *  if it needs to make a deep-copy of the pixels. The bitmap's pixelref will
- *  be shared if either the bitmap is marked as immutable, or canSharePixelRef
- *  is true.
+ *  if it needs to make a deep-copy of the pixels.
+ *
+ *  The bitmap's pixelref will be shared if either the bitmap is marked as
+ *  immutable, or forceSharePixelRef is true.  Shared pixel refs are also
+ *  locked if lockSharedPixelRef is true.
  *

[reed1, 2015/07/27 16:07:56]

Perhaps a note about why one might pass true or false for the last parameter:

e.g. passing true for "lock" allows the image's peekPixels() method to succeed,
but it will force any lazy decodes/generators to execute if they exist on the
pixelref.

[f(malita), 2015/07/27 16:53:39]

Done.

  *  It is illegal to call this with a texture-backed bitmap.
  *
@@ -30,7 +32,7 @@ extern SkImage* SkNewImageFromPixelRef(const SkImageInfo&, SkPixelRef*,
  *  NULL.
  */
 extern SkImage* SkNewImageFromRasterBitmap(const SkBitmap&, bool forceSharePixelRef,
-                                           const SkSurfaceProps*);
+                                           const SkSurfaceProps*, bool lockSharedPixelRef = false);
 
 static inline size_t SkImageMinRowBytes(const SkImageInfo& info) {
     size_t minRB = info.minRowBytes();