cc: Add base64 encoding to picture

cc/resources/picture.cc

Index: cc/resources/picture.cc
diff --git a/cc/resources/picture.cc b/cc/resources/picture.cc
index 2b6eca8777fbc0c3d7d280170d3f7008ce85d990..367e510a272d1ad1c162a4d06083e1aea710da77 100644
--- a/cc/resources/picture.cc
+++ b/cc/resources/picture.cc
@@ -2,15 +2,18 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "cc/resources/picture.h"
+
+#include "base/base64.h"
 #include "base/debug/trace_event.h"
 #include "cc/debug/rendering_stats.h"
 #include "cc/layers/content_layer_client.h"
-#include "cc/resources/picture.h"
 #include "skia/ext/analysis_canvas.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkData.h"
 #include "third_party/skia/include/core/SkDrawFilter.h"
 #include "third_party/skia/include/core/SkPaint.h"
+#include "third_party/skia/include/core/SkStream.h"
 #include "third_party/skia/include/utils/SkPictureUtils.h"
 #include "ui/gfx/rect_conversions.h"
 #include "ui/gfx/skia_util.h"
@@ -178,4 +181,21 @@ void Picture::GatherPixelRefs(const gfx::Rect& layer_rect,
   pixel_refs->unref();
 }
 
+void Picture::AsBase64String(std::string* output) const {
+  SkDynamicMemoryWStream stream;
+  picture_->serialize(&stream);
+  size_t serialized_size = stream.bytesWritten();
+  scoped_ptr<char[]> serialized_picture(new char[serialized_size]);
+  stream.copyTo(serialized_picture.get());
+  base::Base64Encode(std::string(serialized_picture.get(), serialized_size),
+                     output);
+}
+
+void Picture::SetPictureFromBase64String(const std::string & encoded) {
+  std::string decoded;
+  base::Base64Decode(encoded, &decoded);
+  SkMemoryStream stream(decoded.data(), decoded.size());
+  picture_ = skia::AdoptRef(new SkPicture(&stream));
+}
+
 }  // namespace cc