Revert of Move beforeunload hang timer duties to its own timer.

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index 37e0998ab57bd3c844c19e18fb7e7b6761d03b9a..74ee70b1b2541002d192b8df3fbf34ed5a768c1a 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -38,7 +38,6 @@
 #include "content/common/image_downloader/image_downloader.mojom.h"
 #include "content/common/navigation_params.h"
 #include "content/public/browser/render_frame_host.h"
-#include "content/public/browser/renderer_unresponsive_type.h"
 #include "content/public/common/javascript_dialog_type.h"
 #include "content/public/common/previews_state.h"
 #include "media/mojo/interfaces/interface_factory.mojom.h"
@@ -880,9 +879,6 @@
   std::unique_ptr<NavigationHandleImpl> TakeNavigationHandleForCommit(
       const FrameHostMsg_DidCommitProvisionalLoad_Params& params);
 
-  // Called by |beforeunload_timeout_| when the beforeunload timeout fires.
-  void BeforeUnloadTimeout();
-
   // For now, RenderFrameHosts indirectly keep RenderViewHosts alive via a
   // refcount that calls Shutdown when it reaches zero.  This allows each
   // RenderFrameHostManager to just care about RenderFrameHosts, while ensuring
@@ -987,14 +983,6 @@
   // PlzNavigate: all navigations require a beforeUnload ACK.
   bool unload_ack_is_for_navigation_;
 
-  // The timeout monitor that runs from when the beforeunload is started in
-  // DispatchBeforeUnload() until either the render process ACKs it with an IPC
-  // to OnBeforeUnloadACK(), or until the timeout triggers.
-  std::unique_ptr<TimeoutMonitor> beforeunload_timeout_;
-
-  // If beforeunload_timeout_ is active, the type of the timeout.
-  RendererUnresponsiveType beforeunload_timeout_type_;
-
   // Indicates whether this RenderFrameHost is in the process of loading a
   // document or not.
   bool is_loading_;