Fix flakiness when disabling swap out timer in tests.

content/browser/frame_host/render_frame_host_impl.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/frame_host/render_frame_host_impl.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 257 matching lines @@
   if (is_active())
     GetSiteInstance()->DecrementActiveFrameCount();
 
   // If this RenderFrameHost is swapping with a RenderFrameProxyHost, the
   // RenderFrame will already be deleted in the renderer process. Main frame
   // RenderFrames will be cleaned up as part of deleting its RenderView. In all
   // other cases, the RenderFrame should be cleaned up (if it exists).
   if (is_active() && !frame_tree_node_->IsMainFrame() && render_frame_created_)
     Send(new FrameMsg_Delete(routing_id_));
 
-  // NULL out the swapout timer; in crash dumps this member will be null only if
-  // the dtor has run.
+  // Null out the swapout timer; in crash dumps this member will be null only if
+  // the dtor has run.  (It may also be null in tests.)
   swapout_event_monitor_timeout_.reset();
 
   for (const auto& iter: visual_state_callbacks_) {
     iter.second.Run(false);
   }
 
   if (render_widget_host_ &&
       render_widget_host_->owned_by_render_frame_host()) {
     // Shutdown causes the RenderWidgetHost to delete itself.
     render_widget_host_->ShutdownAndDestroyWidget(true);
@@ skipping 884 matching lines @@
   // to be fixed when RenderViewHostImpl::OnSwapOut moves to RenderFrameHost.
   TRACE_EVENT_ASYNC_BEGIN0("navigation", "RenderFrameHostImpl::SwapOut", this);
 
   // If this RenderFrameHost is already pending deletion, it must have already
   // gone through this, therefore just return.
   if (!is_active()) {
     NOTREACHED() << "RFH should be in default state when calling SwapOut.";
     return;
   }
 
-  swapout_event_monitor_timeout_->Start(
-      base::TimeDelta::FromMilliseconds(RenderViewHostImpl::kUnloadTimeoutMS));
+  if (swapout_event_monitor_timeout_) {
+    swapout_event_monitor_timeout_->Start(base::TimeDelta::FromMilliseconds(
+        RenderViewHostImpl::kUnloadTimeoutMS));
+  }
 
   // There may be no proxy if there are no active views in the process.
   int proxy_routing_id = MSG_ROUTING_NONE;
   FrameReplicationState replication_state;
   if (proxy) {
     set_render_frame_proxy_host(proxy);
     proxy_routing_id = proxy->GetRoutingID();
     replication_state = proxy->frame_tree_node()->current_replication_state();
   }
 
@@ skipping 152 matching lines @@
   // |this| may be deleted. Any additional cleanup should happen before
   // the last block of code here.
 }
 
 void RenderFrameHostImpl::OnSwappedOut() {
   // Ignore spurious swap out ack.
   if (!is_waiting_for_swapout_ack_)
     return;
 
   TRACE_EVENT_ASYNC_END0("navigation", "RenderFrameHostImpl::SwapOut", this);
-  swapout_event_monitor_timeout_->Stop();
+  if (swapout_event_monitor_timeout_)
+    swapout_event_monitor_timeout_->Stop();
 
   ClearAllWebUI();
 
   // If this is a main frame RFH that's about to be deleted, update its RVH's
   // swapped-out state here. https://crbug.com/505887
   if (frame_tree_node_->IsMainFrame()) {
     render_view_host_->set_is_active(false);
     render_view_host_->set_is_swapped_out(true);
   }
 
   bool deleted =
       frame_tree_node_->render_manager()->DeleteFromPendingList(this);
   CHECK(deleted);
 }
 
-void RenderFrameHostImpl::ResetSwapOutTimerForTesting() {
-  swapout_event_monitor_timeout_->Stop();
+void RenderFrameHostImpl::DisableSwapOutTimerForTesting() {
+  swapout_event_monitor_timeout_.reset();
 }
 
 void RenderFrameHostImpl::OnContextMenu(const ContextMenuParams& params) {
   // Validate the URLs in |params|.  If the renderer can't request the URLs
   // directly, don't show them in the context menu.
   ContextMenuParams validated_params(params);
   RenderProcessHost* process = GetProcess();
 
   // We don't validate |unfiltered_link_url| so that this field can be used
   // when users want to copy the original link URL.
@@ skipping 1355 matching lines @@
 }
 
 void RenderFrameHostImpl::CreateWebBluetoothService(
     blink::mojom::WebBluetoothServiceRequest request) {
   DCHECK(!web_bluetooth_service_);
   web_bluetooth_service_.reset(
       new WebBluetoothServiceImpl(this, std::move(request)));
 }
 
 }  // namespace content