[DevTools] Filter any messages from previous sessions in DevToolsAgentHostImpl

content/browser/devtools/devtools_agent_host_impl.cc

Index: content/browser/devtools/devtools_agent_host_impl.cc
diff --git a/content/browser/devtools/devtools_agent_host_impl.cc b/content/browser/devtools/devtools_agent_host_impl.cc
index 4d935519c07e0fa2ee919e11ee9ec83bf5e751c8..401a7eba7b41b39b2a2ef1eab3618146262809e0 100644
--- a/content/browser/devtools/devtools_agent_host_impl.cc
+++ b/content/browser/devtools/devtools_agent_host_impl.cc
@@ -76,8 +76,7 @@ scoped_refptr<DevToolsAgentHost> DevToolsAgentHost::GetForWorker(
 }
 
 DevToolsAgentHostImpl::DevToolsAgentHostImpl()
-    : id_(base::GenerateGUID()),
-      client_(NULL) {
+    : id_(base::GenerateGUID()), session_id_(0), client_(NULL) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   g_instances.Get()[id_] = this;
 }
@@ -106,6 +105,7 @@ scoped_refptr<DevToolsAgentHost> DevToolsAgentHost::Create(
 
 void DevToolsAgentHostImpl::AttachClient(DevToolsAgentHostClient* client) {
   scoped_refptr<DevToolsAgentHostImpl> protect(this);
+  ++session_id_;
   if (client_) {
     client_->AgentHostClosed(this, true);
     InnerDetach();
@@ -164,9 +164,13 @@ void DevToolsAgentHostImpl::HostClosed() {
   client->AgentHostClosed(this, false);
 }
 
-void DevToolsAgentHostImpl::SendMessageToClient(const std::string& message) {
+void DevToolsAgentHostImpl::SendMessageToClient(int session_id,
+                                                const std::string& message) {
   if (!client_)
     return;
+  // Filter answer for message that was sent before reattach.

[dgozman, 2015/11/06 22:57:27]

Filter any messages from previous sessions.

[kozy, 2015/11/07 01:54:43]

Done.

+  if (session_id && session_id != session_id_)

[dgozman, 2015/11/06 22:57:27]

Would be great to kill "zero is always valid" case.

[kozy, 2015/11/07 01:54:43]

Done.

+    return;
   client_->DispatchProtocolMessage(this, message);
 }
 
@@ -249,7 +253,7 @@ void DevToolsMessageChunkProcessor::ProcessChunkedMessageFromAgent(
 
   if (chunk.is_first && chunk.is_last) {
     CHECK(message_buffer_size_ == 0);
-    callback_.Run(chunk.data);
+    callback_.Run(chunk.session_id, chunk.data);
     return;
   }
 
@@ -265,7 +269,7 @@ void DevToolsMessageChunkProcessor::ProcessChunkedMessageFromAgent(
 
   if (chunk.is_last) {
     CHECK(message_buffer_.size() == message_buffer_size_);
-    callback_.Run(message_buffer_);
+    callback_.Run(chunk.session_id, message_buffer_);
     message_buffer_ = std::string();
     message_buffer_size_ = 0;
   }