[DevTools] Only create DevToolsAgentHost for main frame and cross-process subframes.

BUG=464993

Review URL: https://codereview.chromium.org/1035793002

Cr-Commit-Position: refs/heads/master@{#322359}

content/browser/devtools/render_frame_devtools_agent_host.cc

@@ -69,6 +69,10 @@ static RenderFrameDevToolsAgentHost* FindAgentHost(WebContents* web_contents) {
   return NULL;
 }
 
+bool ShouldCreateDevToolsFor(RenderFrameHost* rfh) {
+  return rfh->IsCrossProcessSubframe() || !rfh->GetParent();
+}
+
 }  // namespace
 
 scoped_refptr<DevToolsAgentHost>
@@ -95,7 +99,7 @@ void RenderFrameDevToolsAgentHost::AppendAgentHostForFrameIfApplicable(
   RenderFrameHostImpl* rfh = static_cast<RenderFrameHostImpl*>(host);
   if (!rfh->IsRenderFrameLive())
     return;
-  if (rfh->IsCrossProcessSubframe() || !rfh->GetParent())
+  if (ShouldCreateDevToolsFor(rfh))
     result->push_back(RenderFrameDevToolsAgentHost::GetOrCreateFor(rfh));
 }
 
@@ -291,6 +295,12 @@ void RenderFrameDevToolsAgentHost::RenderFrameHostChanged(
 
 void
 RenderFrameDevToolsAgentHost::ReattachToRenderFrameHost(RenderFrameHost* rfh) {
+  if (!ShouldCreateDevToolsFor(rfh)) {
+    DestroyOnRenderFrameGone();
+    // |this| may be deleted at this point.
+    return;
+  }
+
   DCHECK(!reattaching_);
   reattaching_ = true;
   DisconnectRenderFrameHost();
@@ -301,7 +311,11 @@ RenderFrameDevToolsAgentHost::ReattachToRenderFrameHost(RenderFrameHost* rfh) {
 void RenderFrameDevToolsAgentHost::FrameDeleted(RenderFrameHost* rfh) {
   if (rfh != render_frame_host_)
     return;
+  DestroyOnRenderFrameGone();
+  // |this| may be deleted at this point.
+}
 
+void RenderFrameDevToolsAgentHost::DestroyOnRenderFrameGone() {
   DCHECK(render_frame_host_);
   scoped_refptr<RenderFrameDevToolsAgentHost> protect(this);
   HostClosed();
@@ -396,11 +410,9 @@ void RenderFrameDevToolsAgentHost::Observe(int type,
 }
 
 void RenderFrameDevToolsAgentHost::SetRenderFrameHost(RenderFrameHost* rfh) {
+  DCHECK(ShouldCreateDevToolsFor(rfh));
   DCHECK(!render_frame_host_);
   render_frame_host_ = static_cast<RenderFrameHostImpl*>(rfh);
-  // TODO(dgozman): here we should DCHECK that frame host is either root or
-  // cross process subframe, but this requires handling cross-process
-  // navigation. See http://crbug.com/464993.
 
   WebContentsObserver::Observe(WebContents::FromRenderFrameHost(rfh));
   RenderViewHostImpl* rvh = static_cast<RenderViewHostImpl*>(

content/browser/devtools/render_frame_devtools_agent_host.h

@@ -128,6 +128,7 @@ class CONTENT_EXPORT RenderFrameDevToolsAgentHost
   void InnerClientDetachedFromRenderer();
 
   bool IsChildFrame();
+  void DestroyOnRenderFrameGone();
 
   RenderFrameHostImpl* render_frame_host_;
   scoped_ptr<devtools::dom::DOMHandler> dom_handler_;

content/browser/devtools/site_per_process_devtools_browsertest.cc

@@ -103,9 +103,7 @@ IN_PROC_BROWSER_TEST_F(SitePerProcessDevToolsBrowserTest,
   EXPECT_EQ(1U, list.size());
   EXPECT_EQ(DevToolsAgentHost::TYPE_WEB_CONTENTS, list[0]->GetType());
   EXPECT_EQ(main_url.spec(), list[0]->GetURL().spec());
-  // TODO(dgozman): we should get closed notification here.
-  // See http://crbug.com/464993.
-  EXPECT_FALSE(client.closed());
+  EXPECT_TRUE(client.closed());
   child_host->DetachClient();
   child_host = nullptr;
 }