[KeyboardLock] Fixing an F11/JS fullscreen interaction issue

This CL fixes a minor interaction issue where the Fullscreen exit
UI can remain visible when transitioning out of tab initiated
fullscreen into browser fullscreen.  The Exit UI does disappear when
the user releases escape, but we should try to be more proactive and
hide the UI as soon as the transition occurs.  Note: This fix is for
the Aura platforms, I will test on MacOS and make a separate fix
there if needed.

BUG=680809

Change-Id: I0bd375005aef05cacf430d14169f28c43e52c5be
Reviewed-on: https://chromium-review.googlesource.com/1057897Reviewed-by: Yuwei Huang <yuweih@chromium.org>
Commit-Queue: Joe Downing <joedow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#558453}

chrome/browser/ui/views/fullscreen_control/fullscreen_control_host.cc

@@ -97,13 +97,37 @@ void FullscreenControlHost::OnKeyEvent(ui::KeyEvent* event) {
     return;
   }
 
+  ExclusiveAccessManager* const exclusive_access_manager =
+      bubble_views_context_->GetExclusiveAccessManager();
+
+  // FullscreenControlHost UI is not needed for the keyboard input method in any
+  // fullscreen mode except for tab-initiated fullscreen (and only when the user
+  // is required to press and hold the escape key to exit).
+
+  // If we are not in tab-initiated fullscreen, then we want to make sure the
+  // UI exit bubble is not displayed.  This can occur when:
+  // 1.) The user enters browser fullscreen (F11)
+  // 2.) The website then enters tab-initiated fullscreen
+  // 3.) User performs a press and hold gesture on escape
+  //
+  // In this case, the fullscreen controller will revert back to browser
+  // fullscreen mode but there won't be a fullscreen exit message to trigger
+  // the UI cleanup for the exit bubble.  To handle this case, we need to check
+  // to make sure the UI is in the right fullscreen mode before proceeding.
+  if (!exclusive_access_manager->fullscreen_controller()
+           ->IsWindowFullscreenForTabOrPending()) {
+    key_press_delay_timer_.Stop();
+    if (IsVisible() && input_entry_method_ == InputEntryMethod::KEYBOARD)
+      Hide(true);
+    return;
+  }
+
   // Note: This logic handles the UI feedback element used when holding down the
   // esc key, however the logic for exiting fullscreen is handled by the
   // KeyboardLockController class.
   if (event->type() == ui::ET_KEY_PRESSED &&
       !key_press_delay_timer_.IsRunning() &&
-      bubble_views_context_->GetExclusiveAccessManager()
-          ->keyboard_lock_controller()
+      exclusive_access_manager->keyboard_lock_controller()
           ->RequiresPressAndHoldEscToExit()) {
     key_press_delay_timer_.Start(
         FROM_HERE, kKeyPressPopupDelay,