Add buffer helper to read directly into SkString to avoid extra copying

include/core/SkFlattenableBuffers.h

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkFlattenableBuffers_DEFINED
 #define SkFlattenableBuffers_DEFINED
@@ skipping 42 matching lines @@
     // primitives
     virtual bool readBool() = 0;
     virtual SkColor readColor() = 0;
     virtual SkFixed readFixed() = 0;
     virtual int32_t readInt() = 0;
     virtual SkScalar readScalar() = 0;
     virtual uint32_t readUInt() = 0;
     virtual int32_t read32() = 0;
 
     // strings -- the caller is responsible for freeing the string contents
-    virtual char* readString() = 0;
+    virtual void readString(SkString* string) = 0;
     virtual void* readEncodedString(size_t* length, SkPaint::TextEncoding encoding) = 0;
 
     // common data structures
     virtual SkFlattenable* readFlattenable() = 0;
     virtual void readPoint(SkPoint* point) = 0;
     virtual void readMatrix(SkMatrix* matrix) = 0;
     virtual void readIRect(SkIRect* rect) = 0;
     virtual void readRect(SkRect* rect) = 0;
     virtual void readRegion(SkRegion* region) = 0;
     virtual void readPath(SkPath* path) = 0;
@@ skipping 92 matching lines @@
     bool persistTypeface() const { return (fFlags & kCrossProcess_Flag) != 0; }
 
 protected:
     // A helper function so that each subclass does not have to be a friend of SkFlattenable
     void flattenObject(SkFlattenable* obj, SkFlattenableWriteBuffer& buffer);
 
     uint32_t fFlags;
 };
 
 #endif