[DevTools] Fix a couple of issues for cross-site RFDTAH, add a test.

content/browser/devtools/render_frame_devtools_agent_host.cc

Index: content/browser/devtools/render_frame_devtools_agent_host.cc
diff --git a/content/browser/devtools/render_frame_devtools_agent_host.cc b/content/browser/devtools/render_frame_devtools_agent_host.cc
index f6c53011b8cb51f2b54b1e36c01029f7a033e3b6..ebf711133d6cf875f8fc8a8fc5f4a7b152f2f387 100644
--- a/content/browser/devtools/render_frame_devtools_agent_host.cc
+++ b/content/browser/devtools/render_frame_devtools_agent_host.cc
@@ -569,6 +569,9 @@ RenderFrameDevToolsAgentHost::~RenderFrameDevToolsAgentHost() {
 
 void RenderFrameDevToolsAgentHost::ReadyToCommitNavigation(
     NavigationHandle* navigation_handle) {
+  // CommitPending may destruct |this|.
+  scoped_refptr<RenderFrameDevToolsAgentHost> protect(this);
+
   // TODO(clamy): Switch RenderFrameDevToolsAgentHost to always buffer messages
   // until ReadyToCommitNavigation is called, now that it is also called in
   // non-PlzNavigate mode.
@@ -597,6 +600,9 @@ void RenderFrameDevToolsAgentHost::ReadyToCommitNavigation(
 
 void RenderFrameDevToolsAgentHost::DidFinishNavigation(
     NavigationHandle* navigation_handle) {
+  // CommitPending may destruct |this|.
+  scoped_refptr<RenderFrameDevToolsAgentHost> protect(this);
+
   if (!IsBrowserSideNavigationEnabled())
     return;
 
@@ -629,6 +635,9 @@ void RenderFrameDevToolsAgentHost::DidFinishNavigation(
 void RenderFrameDevToolsAgentHost::AboutToNavigateRenderFrame(
     RenderFrameHost* old_host,
     RenderFrameHost* new_host) {
+  // CommitPending may destruct |this|.
+  scoped_refptr<RenderFrameDevToolsAgentHost> protect(this);
+
   if (IsBrowserSideNavigationEnabled())
     return;
 
@@ -662,6 +671,9 @@ void RenderFrameDevToolsAgentHost::AboutToNavigate(
 void RenderFrameDevToolsAgentHost::RenderFrameHostChanged(
     RenderFrameHost* old_host,
     RenderFrameHost* new_host) {
+  // CommitPending may destruct |this|.
+  scoped_refptr<RenderFrameDevToolsAgentHost> protect(this);
+
   target_handler_->UpdateFrames();
 
   if (IsBrowserSideNavigationEnabled())
@@ -819,6 +831,9 @@ void RenderFrameDevToolsAgentHost::DidCommitProvisionalLoadForFrame(
     RenderFrameHost* render_frame_host,
     const GURL& url,
     ui::PageTransition transition_type) {
+  // CommitPending may destruct |this|.
+  scoped_refptr<RenderFrameDevToolsAgentHost> protect(this);
+
   if (IsBrowserSideNavigationEnabled())
     return;
   if (pending_ && pending_->host() == render_frame_host)
@@ -898,6 +913,9 @@ void RenderFrameDevToolsAgentHost::DisconnectWebContents() {
 }
 
 void RenderFrameDevToolsAgentHost::ConnectWebContents(WebContents* wc) {
+  // CommitPending may destruct |this|.
+  scoped_refptr<RenderFrameDevToolsAgentHost> protect(this);
+
   DCHECK(!current_);
   DCHECK(!pending_);
   RenderFrameHostImpl* host =
@@ -930,8 +948,11 @@ std::string RenderFrameDevToolsAgentHost::GetParentId() {
 
 std::string RenderFrameDevToolsAgentHost::GetType() {
   DevToolsManager* manager = DevToolsManager::GetInstance();
-  if (manager->delegate())
-    return manager->delegate()->GetTargetType(current_->host());
+  if (manager->delegate() && current_) {
+    std::string result = manager->delegate()->GetTargetType(current_->host());
+    if (!result.empty())
+      return result;
+  }
   if (IsChildFrame())
     return kTypeFrame;
   return kTypePage;
@@ -939,20 +960,20 @@ std::string RenderFrameDevToolsAgentHost::GetType() {
 
 std::string RenderFrameDevToolsAgentHost::GetTitle() {
   DevToolsManager* manager = DevToolsManager::GetInstance();
-  std::string result;
-  if (manager->delegate())
-    result = manager->delegate()->GetTargetTitle(current_->host());
-  if (!result.empty())
-    return result;
+  if (manager->delegate() && current_) {
+    std::string result = manager->delegate()->GetTargetTitle(current_->host());
+    if (!result.empty())
+      return result;
+  }
   content::WebContents* web_contents = GetWebContents();
   if (web_contents)
-    result = base::UTF16ToUTF8(web_contents->GetTitle());
+    return base::UTF16ToUTF8(web_contents->GetTitle());
   return GetURL().spec();
 }
 
 std::string RenderFrameDevToolsAgentHost::GetDescription() {
   DevToolsManager* manager = DevToolsManager::GetInstance();
-  if (manager->delegate())
+  if (manager->delegate() && current_)
     return manager->delegate()->GetTargetDescription(current_->host());
   return "";
 }