[DevTools] Support multiple clients in DevToolsAgentHost

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 ef1161ecc86426a0cf778303d82e07e98ed9717f..5852ce4dcadc0af7634f9fb2cb6ba9e0127bbcb6 100644
--- a/content/browser/devtools/render_frame_devtools_agent_host.cc
+++ b/content/browser/devtools/render_frame_devtools_agent_host.cc
@@ -182,34 +182,37 @@ void RenderFrameDevToolsAgentHost::FrameHostHolder::Attach(
 
 void RenderFrameDevToolsAgentHost::FrameHostHolder::Reattach(
     FrameHostHolder* old) {
-  int session_id = agent_->session()->session_id();
-  SessionInfo& info = session_infos_[session_id];
-  info.chunk_processor.reset(new DevToolsMessageChunkProcessor(base::Bind(
-      &RenderFrameDevToolsAgentHost::FrameHostHolder::SendChunkedMessage,
-      base::Unretained(this))));
-  SessionInfo* old_info = nullptr;
-  if (old) {
-    auto it = old->session_infos_.find(session_id);
-    old_info = it != old->session_infos_.end() ? &(it->second) : nullptr;
-  }
-  if (old_info)
-    info.chunk_processor->set_state_cookie(
-        old_info->chunk_processor->state_cookie());
-  host_->Send(new DevToolsAgentMsg_Reattach(
-      host_->GetRoutingID(), agent_->GetId(), session_id,
-      info.chunk_processor->state_cookie()));
-  if (old_info) {
-    if (IsBrowserSideNavigationEnabled()) {
-      for (const auto& pair :
-           old_info->sent_messages_whose_reply_came_while_suspended) {
+  for (auto& session_it : agent_->sessions()) {
+    int session_id = session_it.first;
+    SessionInfo& info = session_infos_[session_id];
+    info.chunk_processor.reset(new DevToolsMessageChunkProcessor(base::Bind(
+        &RenderFrameDevToolsAgentHost::FrameHostHolder::SendChunkedMessage,
+        base::Unretained(this))));
+    SessionInfo* old_info = nullptr;
+    if (old) {
+      auto it = old->session_infos_.find(session_id);
+      old_info = it != old->session_infos_.end() ? &(it->second) : nullptr;
+    }
+    if (old_info) {
+      info.chunk_processor->set_state_cookie(
+          old_info->chunk_processor->state_cookie());
+    }
+    host_->Send(new DevToolsAgentMsg_Reattach(
+        host_->GetRoutingID(), agent_->GetId(), session_id,
+        info.chunk_processor->state_cookie()));
+    if (old_info) {
+      if (IsBrowserSideNavigationEnabled()) {
+        for (const auto& pair :
+             old_info->sent_messages_whose_reply_came_while_suspended) {
+          DispatchProtocolMessage(session_id, pair.first, pair.second.method,
+                                  pair.second.message);
+        }
+      }
+      for (const auto& pair : old_info->sent_messages) {
         DispatchProtocolMessage(session_id, pair.first, pair.second.method,
                                 pair.second.message);
       }
     }
-    for (const auto& pair : old_info->sent_messages) {
-      DispatchProtocolMessage(session_id, pair.first, pair.second.method,
-                              pair.second.message);
-    }
   }
   GrantPolicy();
 }
@@ -294,9 +297,9 @@ void RenderFrameDevToolsAgentHost::FrameHostHolder::SendChunkedMessage(
     info.sent_messages_whose_reply_came_while_suspended[id] = sent_message;
     info.pending_messages.push_back(message);
   } else {
-    // Filter any messages from previous sessions.
-    if (agent_->session() && agent_->session()->session_id() == session_id)
-      agent_->session()->SendMessageToClient(message);
+    auto session_it = agent_->sessions().find(session_id);
+    if (session_it != agent_->sessions().end())
+      session_it->second->SendMessageToClient(message);
     // |this| may be deleted at this point.
   }
 }
@@ -309,9 +312,10 @@ void RenderFrameDevToolsAgentHost::FrameHostHolder::Resume() {
   suspended_ = false;
   for (auto& it : session_infos_) {
     SessionInfo& info = it.second;
-    if (agent_->session() && agent_->session()->session_id() == it.first) {
+    auto session_it = agent_->sessions().find(it.first);
+    if (session_it != agent_->sessions().end()) {
       for (const std::string& message : info.pending_messages)
-        agent_->session()->SendMessageToClient(message);
+        session_it->second->SendMessageToClient(message);
     }
     std::vector<std::string> empty;
     info.pending_messages.swap(empty);
@@ -595,7 +599,8 @@ void RenderFrameDevToolsAgentHost::AttachSession(DevToolsSession* session) {
     current_->Attach(session);
   if (pending_)
     pending_->Attach(session);
-  OnClientAttached();
+  if (sessions().size() == 1)
+    OnClientsAttached();
 }
 
 void RenderFrameDevToolsAgentHost::DetachSession(int session_id) {
@@ -603,7 +608,8 @@ void RenderFrameDevToolsAgentHost::DetachSession(int session_id) {
     current_->Detach(session_id);
   if (pending_)
     pending_->Detach(session_id);
-  OnClientDetached();
+  if (sessions().empty())
+    OnClientsDetached();
 }
 
 bool RenderFrameDevToolsAgentHost::DispatchProtocolMessage(
@@ -644,7 +650,7 @@ void RenderFrameDevToolsAgentHost::InspectElement(
     pending_->InspectElement(session->session_id(), x, y);
 }
 
-void RenderFrameDevToolsAgentHost::OnClientAttached() {
+void RenderFrameDevToolsAgentHost::OnClientsAttached() {
   if (!web_contents())
     return;
 
@@ -652,7 +658,7 @@ void RenderFrameDevToolsAgentHost::OnClientAttached() {
   CreatePowerSaveBlocker();
 }
 
-void RenderFrameDevToolsAgentHost::OnClientDetached() {
+void RenderFrameDevToolsAgentHost::OnClientsDetached() {
 #if defined(OS_ANDROID)
   power_save_blocker_.reset();
 #endif
@@ -847,8 +853,8 @@ void RenderFrameDevToolsAgentHost::DestroyOnRenderFrameGone() {
   scoped_refptr<RenderFrameDevToolsAgentHost> protect(this);
   UpdateProtocolHandlers(nullptr);
   if (IsAttached())
-    OnClientDetached();
-  ForceDetach(false);
+    OnClientsDetached();
+  ForceDetachAllClients(false);
   pending_.reset();
   current_.reset();
   frame_tree_node_ = nullptr;
@@ -1007,8 +1013,8 @@ void RenderFrameDevToolsAgentHost::UpdateProtocolHandlers(
   }
 #endif
   handlers_frame_host_ = host;
-  if (session())
-    session()->SetRenderFrameHost(host);
+  for (auto& it : sessions())
+    it.second->SetRenderFrameHost(host);
 }
 
 void RenderFrameDevToolsAgentHost::DisconnectWebContents() {