Reland Trace FrameTreeNode Snapshots

content/browser/frame_host/traced_frame_tree_node.cc

+// Copyright 2016 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_node.h"
+
+#include "base/command_line.h"
+#include "base/json/json_writer.h"
+#include "base/strings/stringprintf.h"
+#include "content/browser/frame_host/frame_tree.h"
+#include "content/public/common/content_switches.h"
+#include "url/gurl.h"
+
+namespace content {
+
+TracedFrameTreeNode::TracedFrameTreeNode(const FrameTreeNode& node)
+    : parent_node_id_(-1),
+      process_id_(-1),
+      routing_id_(-1) {
+  FrameTreeNode* parent = node.parent();
+  if (parent)
+    parent_node_id_ = parent->frame_tree_node_id();
+
+  RenderFrameHostImpl* current_frame_host = node.current_frame_host();
+
+  if (current_frame_host->last_committed_url().is_valid())
+    url_ = current_frame_host->last_committed_url().spec();
+
+  // On Windows, |rph->GetHandle()| does not duplicate ownership
+  // of the process handle and the render host still retains it. Therefore, we
+  // cannot create a base::Process object, which provides a proper way to get a
+  // process id, from the handle. For a stopgap, we use this deprecated
+  // function that does not require the ownership (http://crbug.com/417532).
+  process_id_ = base::GetProcId(current_frame_host->GetProcess()->GetHandle());
+
+  routing_id_ = current_frame_host->GetRoutingID();
+  DCHECK_NE(routing_id_, MSG_ROUTING_NONE);
+}
+
+TracedFrameTreeNode::~TracedFrameTreeNode() {
+}
+
+void TracedFrameTreeNode::AppendAsTraceFormat(std::string* out) const {
+  scoped_ptr<base::DictionaryValue> value(new base::DictionaryValue());
+
+  if (parent_node_id_ >= 0) {
+    scoped_ptr<base::DictionaryValue> ref(new base::DictionaryValue());
+    ref->SetString("id_ref", base::StringPrintf("0x%x", parent_node_id_));
+    ref->SetString("scope", "FrameTreeNode");
+    value->Set("parent", std::move(ref));
+  }
+
+  if (process_id_ >= 0) {
+    scoped_ptr<base::DictionaryValue> ref(new base::DictionaryValue());
+    ref->SetInteger("pid_ref", process_id_);
+    ref->SetString("id_ref", base::StringPrintf("0x%x", routing_id_));
+    ref->SetString("scope", "RenderFrame");
+    value->Set("RenderFrame", std::move(ref));
+  }
+
+  if (!url_.empty())
+    value->SetString("url", url_);
+
+  std::string tmp;
+  base::JSONWriter::Write(*value, &tmp);
+  *out += tmp;
+}
+
+}  // content