Trace FrameTreeNode Snapshots

content/browser/frame_host/traced_frame_tree.h

Index: content/browser/frame_host/traced_frame_tree.h
diff --git a/content/browser/frame_host/traced_frame_tree.h b/content/browser/frame_host/traced_frame_tree.h
new file mode 100644
index 0000000000000000000000000000000000000000..7653112ac3f461eef11ee29aa49f29e54b982cbb
--- /dev/null
+++ b/content/browser/frame_host/traced_frame_tree.h
@@ -0,0 +1,33 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/trace_event/trace_event_impl.h"
+#include "base/values.h"
+#include "content/common/content_export.h"
+#include "url/gurl.h"
+
+namespace content {
+
+class FrameTree;
+
+// This is a temporary container used when tracing snapshots of FrameTree
+// objects. When a snapshot of a FrameTree is taken, a TracedFrameTree is
+// created and stored by the tracing system until the trace is dumped.
+class CONTENT_EXPORT TracedFrameTree :
+  public base::trace_event::ConvertableToTraceFormat {
+ public:
+  static scoped_refptr<TracedFrameTree> Create(const FrameTree& tree);
+
+  void AppendAsTraceFormat(std::string* out) const override;
+
+ private:
+  explicit TracedFrameTree(const FrameTree& tree);
+  ~TracedFrameTree() override;
+
+  scoped_ptr<base::DictionaryValue> value_;
+
+  DISALLOW_COPY_AND_ASSIGN(TracedFrameTree);
+};
+
+}  // content