Remove duplicate definition of kTitlebarAnimationDelay

kTitlebarAnimationDelay is defined twice in
browser_non_client_frame_view_ash.cc likely due to a bad merge of
https://chromium-review.googlesource.com/c/chromium/src/+/1055228.
This CL removes the reduntant constant definition.

Bug: 836482
Change-Id: I755c84182da0348b5e701bec2f6ad24cb9b8c0b9
Reviewed-on: https://chromium-review.googlesource.com/1088460Reviewed-by: Michael Wasserman <msw@chromium.org>
Commit-Queue: Alan Cutter <alancutter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#565128}

chrome/browser/ui/views/frame/browser_non_client_frame_view_ash.cc

@@ -740,8 +740,6 @@ BrowserNonClientFrameViewAsh::CreateFrameHeader() {
       AddChildView(frame_header_origin_text_);
 
       // Schedule the title bar animation.
-      constexpr base::TimeDelta kTitlebarAnimationDelay =
-          base::TimeDelta::FromMilliseconds(750);
       base::SequencedTaskRunnerHandle::Get()->PostDelayedTask(
           FROM_HERE,
           base::BindOnce(&BrowserNonClientFrameViewAsh::StartHostedAppAnimation,