Trace FrameTreeNode Snapshots

content/browser/frame_host/traced_frame_tree.cc

Index: content/browser/frame_host/traced_frame_tree.cc
diff --git a/content/browser/frame_host/traced_frame_tree.cc b/content/browser/frame_host/traced_frame_tree.cc
new file mode 100644
index 0000000000000000000000000000000000000000..70ed199626883b024fb4534940e5bfefda39b9bd
--- /dev/null
+++ b/content/browser/frame_host/traced_frame_tree.cc
@@ -0,0 +1,58 @@
+// 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 "content/browser/frame_host/traced_frame_tree.h"
+
+#include "base/command_line.h"
+#include "base/json/json_writer.h"
+#include "content/browser/frame_host/frame_tree.h"
+#include "content/public/common/content_switches.h"
+
+namespace content {
+
+namespace {
+
+scoped_ptr<base::DictionaryValue> GetFrameTreeNodeAsValue(FrameTreeNode* node) {
+  scoped_ptr<base::DictionaryValue> value(new base::DictionaryValue());
+  value->SetString("url", node->current_url().spec());
+  value->SetInteger("nodeId", node->frame_tree_node_id());
+
+  RenderFrameHostImpl* current_frame_host =
+      node->render_manager()->current_frame_host();
+  if (current_frame_host) {

[clamy, 2015/10/29 17:17:16]

We should always have a current RFH, so I think we can just DCHECK here.

+    value->SetInteger("processId", current_frame_host->GetProcess()->GetID());
+    value->SetInteger("routingId", current_frame_host->GetRoutingID());
+  }
+
+  if (node->child_count() > 0) {
+    scoped_ptr<base::ListValue> subframes(new base::ListValue());
+    for (size_t i = 0; i < node->child_count(); ++i) {
+      subframes->Append(GetFrameTreeNodeAsValue(node->child_at(i)));
+    }
+    value->Set("children", subframes.Pass());
+  }
+  return value.Pass();
+}
+
+}  // namespace
+
+scoped_refptr<TracedFrameTree> TracedFrameTree::Create(const FrameTree& tree) {
+  return scoped_refptr<TracedFrameTree>(new TracedFrameTree(
+        GetFrameTreeNodeAsValue(tree.root())));
+}
+
+TracedFrameTree::TracedFrameTree(scoped_ptr<base::DictionaryValue> value)
+    : value_(value.Pass()) {
+}
+
+TracedFrameTree::~TracedFrameTree() {
+}
+
+void TracedFrameTree::AppendAsTraceFormat(std::string* out) const {
+  std::string tmp;
+  base::JSONWriter::Write(*value_, &tmp);
+  *out += tmp;
+}
+
+}  // content