Adding release method to SkWriter32 and using it to not copy the ops data from SkPictureRecord to S…

include/core/SkWriter32.h

Index: include/core/SkWriter32.h
diff --git a/include/core/SkWriter32.h b/include/core/SkWriter32.h
index 7d8d764e5944123a0819204dd0863f6a1b84bacb..4bff6933c4f56cf87c215bd13a339f5a67659c8c 100644
--- a/include/core/SkWriter32.h
+++ b/include/core/SkWriter32.h
@@ -21,6 +21,8 @@
 #include "SkTDArray.h"
 #include "SkTypes.h"
 
+class SkData;
+
 class SkWriter32 : SkNoncopyable {
 public:
     /**
@@ -31,10 +33,10 @@ public:
      *  This used to be optional behavior, but pipe now relies on it.
      */
     SkWriter32(void* external = NULL, size_t externalBytes = 0)
-        : fData(0)
+        : fData(NULL)
         , fCapacity(0)
         , fUsed(0)
-        , fExternal(0)
+        , fExternal(NULL)
     {
         this->reset(external, externalBytes);
     }
@@ -229,6 +231,13 @@ public:
         return stream->read(this->reservePad(length), length);
     }
 
+    /**
+     *  Release the internal buffer to the caller in an SkData.
+     *  The caller must call unref() when it is finished using the data.
+     *  This also clears the writer to empty as if you had called reset().
+     */
+    SkData* detatchAsData();
+
 private:
     void growToAtLeast(size_t size);