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

src/core/SkWriter32.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkReader32.h"
 #include "SkString.h"
 #include "SkWriter32.h"
+#include "SkData.h"
 
 /*
  *  Strings are stored as: length[4-bytes] + string_data + '\0' + pad_to_mul_4
  */
 
 const char* SkReader32::readString(size_t* outLen) {
     size_t len = this->readInt();
     const void* ptr = this->peek();
 
     // skip over the string + '\0' and then pad to a multiple of 4
@@ skipping 56 matching lines @@
     // cause the buffer to grow
     fInternal.setCountExact(fCapacity);
     fData = fInternal.begin();
     if (wasExternal) {
         // we were external, so copy in the data
         memcpy(fData, fExternal, fUsed);
     }
     SkASSERT(fInternal.count() == fCapacity);
     SkASSERT(fInternal.reserved() == fCapacity);
 }
+
+SkData* SkWriter32::detatchAsData() {
+    uint8_t* buffer = NULL;
+    if ((fExternal != NULL) && (fData == fExternal)) {
+        // We need to copy to an allocated buffer before returning.
+        buffer = (uint8_t*)sk_malloc_throw(fUsed);
+        memcpy(buffer, fData, fUsed);
+    } else {
+        buffer = fInternal.detach();
+    }
+    SkData* data = SkData::NewFromMalloc(buffer, fUsed);
+    fData = NULL;

[tomhudson, 2014/02/07 17:15:58]

Nit: the constructor uses 0 for all 4 fields.
I think this usage of NULL is more in line with Skia style - worth fixing the
inconsistency?

[iancottrell, 2014/02/11 13:28:40]

Done.

+    fCapacity = 0;
+    fUsed = 0;
+    fExternal = NULL;
+    return data;
+}