Remove RenderThreadImpl::DoNotSuspendWebKitSharedTimer

Shared timers are explicitly suppressed when sending a sync IPC that
runs a nested message loop. Historically, there was an affordance for
avoiding this suppression, but it appears that is no longer necessary.
Remove RenderThreadImpl::DoNotSuspendWebKitSharedTimer accordingly.

BUG=none

Review URL: https://codereview.chromium.org/1132913002

Cr-Commit-Position: refs/heads/master@{#329225}
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 82748e9a..fe0ca04 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -214,12 +214,11 @@
   GpuChannelHost* EstablishGpuChannelSync(CauseForGpuLaunch);
 
 
-  // These methods modify how the next message is sent.  Normally, when sending
+  // This method modifies how the next message is sent.  Normally, when sending
   // a synchronous message that runs a nested message loop, we need to suspend
   // callbacks into WebKit.  This involves disabling timers and deferring
   // resource loads.  However, there are exceptions when we need to customize
   // the behavior.
-  void DoNotSuspendWebKitSharedTimer();
   void DoNotNotifyWebKitOfModalLoop();
 
   // True if we are running layout tests. This currently disables forwarding
@@ -533,7 +532,6 @@
   // The number of idle handler calls that skip sending idle notifications.
   int idle_notifications_to_skip_;
 
-  bool suspend_webkit_shared_timer_;
   bool notify_webkit_of_modal_loop_;
   bool webkit_shared_timer_suspended_;