[DevTools] Support multiple DevToolsMessageChunkProcessor instances

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 d572f3a01ce58545eedcd97df0338556273a8d8d..ef1161ecc86426a0cf778303d82e07e98ed9717f 100644
--- a/content/browser/devtools/render_frame_devtools_agent_host.cc
+++ b/content/browser/devtools/render_frame_devtools_agent_host.cc
@@ -7,6 +7,7 @@
 #include <tuple>
 #include <utility>
 
+#include "base/containers/flat_map.h"
 #include "base/guid.h"
 #include "base/json/json_reader.h"
 #include "base/lazy_instance.h"
@@ -118,6 +119,7 @@ class RenderFrameDevToolsAgentHost::FrameHostHolder {
   void Attach(DevToolsSession* session);
   void Reattach(FrameHostHolder* old);
   void Detach(int session_id);
+  void Disconnect();
   void DispatchProtocolMessage(int session_id,
                                int call_id,
                                const std::string& method,
@@ -130,36 +132,40 @@ class RenderFrameDevToolsAgentHost::FrameHostHolder {
  private:
   void GrantPolicy();
   void RevokePolicy();
-  void SendMessageToClient(int session_id, const std::string& message);
+  void SendChunkedMessage(int session_id, const std::string& message);
+
+  struct MethodAndMessage {
+    std::string method;
+    std::string message;
+  };
+
+  struct SessionInfo {
+    std::unique_ptr<DevToolsMessageChunkProcessor> chunk_processor;
+    std::vector<std::string> pending_messages;
+    // <call_id> -> MethodAndMessage
+    std::map<int, MethodAndMessage> sent_messages;
+    // These are sent messages for which we got a reply while suspended.
+    std::map<int, MethodAndMessage>
+        sent_messages_whose_reply_came_while_suspended;
+  };
 
   RenderFrameDevToolsAgentHost* agent_;
   RenderFrameHostImpl* host_;
-  bool attached_;
   bool suspended_;
-  DevToolsMessageChunkProcessor chunk_processor_;
-  // <session_id, message>
-  std::vector<std::pair<int, std::string>> pending_messages_;
-  // <call_id> -> PendingMessage
-  std::map<int, PendingMessage> sent_messages_;
-  // These are sent messages for which we got a reply while suspended.
-  std::map<int, PendingMessage> sent_messages_whose_reply_came_while_suspended_;
+  bool disconnected_;
+  base::flat_map<int, SessionInfo> session_infos_;
 };
 
 RenderFrameDevToolsAgentHost::FrameHostHolder::FrameHostHolder(
-    RenderFrameDevToolsAgentHost* agent, RenderFrameHostImpl* host)
-    : agent_(agent),
-      host_(host),
-      attached_(false),
-      suspended_(false),
-      chunk_processor_(base::Bind(
-           &RenderFrameDevToolsAgentHost::FrameHostHolder::SendMessageToClient,
-           base::Unretained(this))) {
+    RenderFrameDevToolsAgentHost* agent,
+    RenderFrameHostImpl* host)
+    : agent_(agent), host_(host), suspended_(false), disconnected_(false) {
   DCHECK(agent_);
   DCHECK(host_);
 }
 
 RenderFrameDevToolsAgentHost::FrameHostHolder::~FrameHostHolder() {
-  if (attached_)
+  if (!disconnected_ && !session_infos_.empty())
     RevokePolicy();
 }
 
@@ -168,37 +174,57 @@ void RenderFrameDevToolsAgentHost::FrameHostHolder::Attach(
   host_->Send(new DevToolsAgentMsg_Attach(
       host_->GetRoutingID(), agent_->GetId(), session->session_id()));
   GrantPolicy();
-  attached_ = true;
+  SessionInfo& info = session_infos_[session->session_id()];
+  info.chunk_processor.reset(new DevToolsMessageChunkProcessor(base::Bind(
+      &RenderFrameDevToolsAgentHost::FrameHostHolder::SendChunkedMessage,
+      base::Unretained(this))));
 }
 
 void RenderFrameDevToolsAgentHost::FrameHostHolder::Reattach(
     FrameHostHolder* old) {
-  if (old)
-    chunk_processor_.set_state_cookie(old->chunk_processor_.state_cookie());
-  host_->Send(new DevToolsAgentMsg_Reattach(
-      host_->GetRoutingID(), agent_->GetId(), agent_->session()->session_id(),
-      chunk_processor_.state_cookie()));
+  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->sent_messages_whose_reply_came_while_suspended_) {
-        DispatchProtocolMessage(pair.second.session_id, pair.first,
-                                pair.second.method, pair.second.message);
+           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->sent_messages_) {
-      DispatchProtocolMessage(pair.second.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();
-  attached_ = true;
 }
 
 void RenderFrameDevToolsAgentHost::FrameHostHolder::Detach(int session_id) {
   host_->Send(new DevToolsAgentMsg_Detach(host_->GetRoutingID(), session_id));
   RevokePolicy();
-  attached_ = false;
+  session_infos_.erase(session_id);
+}
+
+void RenderFrameDevToolsAgentHost::FrameHostHolder::Disconnect() {
+  for (auto& it : session_infos_)
+    host_->Send(new DevToolsAgentMsg_Detach(host_->GetRoutingID(), it.first));
+  RevokePolicy();
+  disconnected_ = true;
 }
 
 void RenderFrameDevToolsAgentHost::FrameHostHolder::GrantPolicy() {
@@ -235,12 +261,12 @@ void RenderFrameDevToolsAgentHost::FrameHostHolder::DispatchProtocolMessage(
     const std::string& message) {
   host_->Send(new DevToolsAgentMsg_DispatchOnInspectorBackend(
       host_->GetRoutingID(), session_id, call_id, method, message));
-  sent_messages_[call_id] = { session_id, method, message };
+  session_infos_[session_id].sent_messages[call_id] = {method, message};
 }
 
 void RenderFrameDevToolsAgentHost::FrameHostHolder::InspectElement(
     int session_id, int x, int y) {
-  DCHECK(attached_);
+  DCHECK(session_infos_.find(session_id) != session_infos_.end());
   host_->Send(new DevToolsAgentMsg_InspectElement(
       host_->GetRoutingID(), session_id, x, y));
 }
@@ -248,20 +274,29 @@ void RenderFrameDevToolsAgentHost::FrameHostHolder::InspectElement(
 bool
 RenderFrameDevToolsAgentHost::FrameHostHolder::ProcessChunkedMessageFromAgent(
     const DevToolsMessageChunk& chunk) {
-  return chunk_processor_.ProcessChunkedMessageFromAgent(chunk);
+  auto it = session_infos_.find(chunk.session_id);
+  if (it != session_infos_.end())
+    return it->second.chunk_processor->ProcessChunkedMessageFromAgent(chunk);
+  return false;
 }
 
-void RenderFrameDevToolsAgentHost::FrameHostHolder::SendMessageToClient(
+void RenderFrameDevToolsAgentHost::FrameHostHolder::SendChunkedMessage(
     int session_id,
     const std::string& message) {
-  int id = chunk_processor_.last_call_id();
-  PendingMessage sent_message = sent_messages_[id];
-  sent_messages_.erase(id);
+  auto it = session_infos_.find(session_id);
+  if (it == session_infos_.end())
+    return;
+  SessionInfo& info = it->second;
+  int id = info.chunk_processor->last_call_id();
+  MethodAndMessage sent_message = info.sent_messages[id];
+  info.sent_messages.erase(id);
   if (suspended_) {
-    sent_messages_whose_reply_came_while_suspended_[id] = sent_message;
-    pending_messages_.push_back(std::make_pair(session_id, message));
+    info.sent_messages_whose_reply_came_while_suspended[id] = sent_message;
+    info.pending_messages.push_back(message);
   } else {
-    agent_->SendMessageToClient(session_id, message);
+    // Filter any messages from previous sessions.
+    if (agent_->session() && agent_->session()->session_id() == session_id)
+      agent_->session()->SendMessageToClient(message);
     // |this| may be deleted at this point.
   }
 }
@@ -272,11 +307,16 @@ void RenderFrameDevToolsAgentHost::FrameHostHolder::Suspend() {
 
 void RenderFrameDevToolsAgentHost::FrameHostHolder::Resume() {
   suspended_ = false;
-  for (const auto& pair : pending_messages_)
-    agent_->SendMessageToClient(pair.first, pair.second);
-  std::vector<std::pair<int, std::string>> empty;
-  pending_messages_.swap(empty);
-  sent_messages_whose_reply_came_while_suspended_.clear();
+  for (auto& it : session_infos_) {
+    SessionInfo& info = it.second;
+    if (agent_->session() && agent_->session()->session_id() == it.first) {
+      for (const std::string& message : info.pending_messages)
+        agent_->session()->SendMessageToClient(message);
+    }
+    std::vector<std::string> empty;
+    info.pending_messages.swap(empty);
+    info.sent_messages_whose_reply_came_while_suspended.clear();
+  }
 }
 
 // RenderFrameDevToolsAgentHost ------------------------------------------------
@@ -976,8 +1016,7 @@ void RenderFrameDevToolsAgentHost::DisconnectWebContents() {
     DiscardPending();
   UpdateProtocolHandlers(nullptr);
   disconnected_ = std::move(current_);
-  if (session())
-    disconnected_->Detach(session()->session_id());
+  disconnected_->Disconnect();
   frame_tree_node_ = nullptr;
   in_navigation_protocol_message_buffer_.clear();
   navigating_handles_.clear();