Add 'NavigationHandle::QueueConsoleMessage'.

content/browser/frame_host/navigation_handle_impl.cc

Index: content/browser/frame_host/navigation_handle_impl.cc
diff --git a/content/browser/frame_host/navigation_handle_impl.cc b/content/browser/frame_host/navigation_handle_impl.cc
index a31508c18e0e1ec27973f27cbb510d2398d4090a..74b3559bd73818e55b1f9b46a266433d7fb22573 100644
--- a/content/browser/frame_host/navigation_handle_impl.cc
+++ b/content/browser/frame_host/navigation_handle_impl.cc
@@ -390,6 +390,13 @@ void NavigationHandleImpl::WillProcessResponse(
   state_ = WILL_PROCESS_RESPONSE;
   complete_callback_ = callback;
 
+  // Clear out the pending console message queue now that we have a
+  // render_frame_host.
+  //
+  // TODO(mkwst): Move this to 'ReadyToCommitNavigation' as part of the work
+  // in https://crbug.com/621856.
+  DumpMessagesToConsole();
+
   // Notify each throttle of the response.
   NavigationThrottle::ThrottleCheckResult result = CheckWillProcessResponse();
 
@@ -431,6 +438,14 @@ void NavigationHandleImpl::DidCommitNavigation(
   state_ = net_error_code_ == net::OK ? DID_COMMIT : DID_COMMIT_ERROR_PAGE;
 }
 
+void NavigationHandleImpl::QueueConsoleMessage(ConsoleMessageLevel level,
+                                               const std::string& message) {
+  console_queue_.emplace(level, message);
+
+  if (state_ >= WILL_PROCESS_RESPONSE)
+    DumpMessagesToConsole();
+}
+
 NavigationThrottle::ThrottleCheckResult
 NavigationHandleImpl::CheckWillStartRequest() {
   DCHECK(state_ == WILL_SEND_REQUEST || state_ == DEFERRING_START);
@@ -541,4 +556,15 @@ void NavigationHandleImpl::RunCompleteCallback(
   // destruction.
 }
 
+void NavigationHandleImpl::DumpMessagesToConsole() {
+  DCHECK_GE(state_, WILL_PROCESS_RESPONSE);
+  DCHECK(GetRenderFrameHost());
+
+  while (!console_queue_.empty()) {
+    GetRenderFrameHost()->AddMessageToConsole(console_queue_.front().first,
+                                              console_queue_.front().second);
+    console_queue_.pop();
+  }
+}
+
 }  // namespace content