DevTools: allow embedder handling async remote debugger commands.

content/browser/devtools/devtools_session.cc

Index: content/browser/devtools/devtools_session.cc
diff --git a/content/browser/devtools/devtools_session.cc b/content/browser/devtools/devtools_session.cc
index 8783f1723c2ff77a19c1524491e513fe2315a34f..cfd8f18ef2bfd14dfc56de3db7a1a5d537c14b18 100644
--- a/content/browser/devtools/devtools_session.cc
+++ b/content/browser/devtools/devtools_session.cc
@@ -13,16 +13,15 @@
 
 namespace content {
 
-DevToolsSession::DevToolsSession(
-    DevToolsAgentHostImpl* agent_host,
-    DevToolsAgentHostClient* client,
-    int session_id)
+DevToolsSession::DevToolsSession(DevToolsAgentHostImpl* agent_host,
+                                 DevToolsAgentHostClient* client,
+                                 int session_id)
     : agent_host_(agent_host),
       client_(client),
       session_id_(session_id),
       host_(nullptr),
-      dispatcher_(new protocol::UberDispatcher(this)) {
-}
+      dispatcher_(new protocol::UberDispatcher(this)),
+      weak_factory_(this) {}
 
 DevToolsSession::~DevToolsSession() {
   dispatcher_.reset();
@@ -48,6 +47,13 @@ void DevToolsSession::SetFallThroughForNotFound(bool value) {
   dispatcher_->setFallThroughForNotFound(value);
 }
 
+void DevToolsSession::sendResponse(
+    std::unique_ptr<base::DictionaryValue> response) {
+  std::string json;
+  base::JSONWriter::Write(*response.get(), &json);
+  agent_host_->SendMessageToClient(session_id_, json);
+}
+
 protocol::Response::Status DevToolsSession::Dispatch(
     const std::string& message,
     int* call_id,
@@ -61,11 +67,15 @@ protocol::Response::Status DevToolsSession::Dispatch(
         agent_host_,
         static_cast<base::DictionaryValue*>(value.get())));

[pfeldman, 2017/02/21 19:10:24]

nit: extract variable.

     if (response) {
-      std::string json;
-      base::JSONWriter::Write(*response.get(), &json);
-      agent_host_->SendMessageToClient(session_id_, json);
+      sendResponse(std::move(response));
       return protocol::Response::kSuccess;
     }
+    if (delegate->HandleAsyncCommand(
+            agent_host_, static_cast<base::DictionaryValue*>(value.get()),
+            base::Bind(&DevToolsSession::sendResponse,
+                       weak_factory_.GetWeakPtr()))) {
+      return protocol::Response::kAsync;
+    }
   }
 
   return dispatcher_->dispatch(protocol::toProtocolValue(value.get(), 1000),