Create a new RenderFrameHost per child frame when --site-per-process is enabled.

content/browser/renderer_host/frame_tree.cc

+// Copyright 2013 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/renderer_host/frame_tree.h"
+
+#include <queue>
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "content/browser/renderer_host/frame_tree_node.h"
+#include "content/browser/renderer_host/render_frame_host_impl.h"
+
+namespace content {
+
+namespace {
+bool FindHelper(int64 frame_id, FrameTreeNode** out_node,
+                FrameTreeNode* node) {
+  if (node->frame_id() == frame_id) {
+    *out_node = node;
+    return false;

[nasko, 2013/09/11 22:26:24]

Put a comment on why we return false. It is not immediately obvious and
returning false when node is found is counterintuitive.

[awong, 2013/09/21 01:19:56]

Done.

+  }
+  return true;
+}
+
+}  // namespace
+
+FrameTree::FrameTree()
+    : root_(new FrameTreeNode(FrameTreeNode::kInvalidFrameId, std::string(),
+                              scoped_ptr<RenderFrameHostImpl>())) {
+}
+
+FrameTree::~FrameTree() {
+}
+
+FrameTreeNode* FrameTree::FindByID(int64 frame_id) {
+  FrameTreeNode* node = NULL;
+  ForEach(base::Bind(&FindHelper, frame_id, &node));
+  return node;
+}
+
+void FrameTree::ForEach(
+    const base::Callback<bool(FrameTreeNode*)>& on_node) const {
+  std::queue<FrameTreeNode*> queue;
+  queue.push(root_.get());
+
+  while (!queue.empty()) {
+    FrameTreeNode* node = queue.front();
+    queue.pop();
+    if (!on_node.Run(node))
+      break;
+
+    for (size_t i = 0; i < node->child_count(); ++i)
+      queue.push(node->child_at(i));
+  }
+}
+
+bool FrameTree::IsFirstNavigation() const {
+  return root_->frame_id() == FrameTreeNode::kInvalidFrameId;
+}
+
+void FrameTree::OnFirstNavigation(int main_frame_id) {
+  root_->set_frame_id(main_frame_id);
+}
+
+void FrameTree::AddFrame(int render_frame_host_id, int64 parent_frame_id,
+                         int64 frame_id, const std::string& frame_name) {
+  FrameTreeNode* parent = FindByID(parent_frame_id);
+  parent->AddChild(CreateNode(frame_id, frame_name, render_frame_host_id,
+                              parent->render_frame_host()->GetProcess()));
+}
+
+void FrameTree::RemoveFrame(int64 parent_frame_id, int64 frame_id) {
+  FrameTreeNode* parent = FindByID(parent_frame_id);
+
+  // TODO(ajwong): Should this DCHECK()?

[nasko, 2013/09/11 22:26:24]

Yes, it will be helpful to DCHECK here.

[awong, 2013/09/21 01:19:56]

Just removed the check cause we crash immediately.

[Charlie Reis, 2013/09/24 18:25:58]

Is this done in response to a message from the renderer?  If so, we should keep
the null check and leave out a DCHECK.  Otherwise the renderer can pass a fake
frame_id to kill the browser process.

+  if (!parent)
+    return;
+
+  parent->RemoveChild(frame_id);
+  if (!on_frame_removed_.is_null())
+    on_frame_removed_.Run(frame_id);
+}
+
+void FrameTree::SetFrameUrl(int64 frame_id, const GURL& url) {
+  FrameTreeNode* node = FindByID(frame_id);
+  if (node)
+    node->set_current_url(url);
+}
+
+scoped_ptr<RenderFrameHostImpl> FrameTree::SwapMainFrame(
+    scoped_ptr<RenderFrameHostImpl> render_frame_host) {
+  return root_->ResetRenderFrameHost(render_frame_host.Pass());
+}
+
+RenderFrameHostImpl* FrameTree::GetMainFrame() const {
+  return root_->render_frame_host();
+}
+
+void FrameTree::SetFrameRemoveListener(
+    const base::Callback<void(int64)>& on_frame_removed) {
+  on_frame_removed_ = on_frame_removed;
+}
+
+scoped_ptr<FrameTreeNode> FrameTree::CreateNode(
+    int64 frame_id, const std::string& frame_name, int render_frame_host_id,
+    RenderProcessHost* render_process_host) {
+  scoped_ptr<RenderFrameHostImpl> render_frame_host(
+      new RenderFrameHostImpl(render_process_host, this, render_frame_host_id,
+                              false));
+
+  return make_scoped_ptr(new FrameTreeNode(frame_id, frame_name,
+                                           render_frame_host.Pass()));
+}
+
+}  // namespace content