[Locked Fullscreen] Disable ARC while in locked fullscreen

Locked fullscreen is supposed to be a secure mode where the user cannot do
anything outside of the current browser window, but ARC apps can currently draw
on top of it.  To fix this, we disable ARC when entering the mode, and we
re-enable it upon exiting the mode.

Bug: 888611
Change-Id: I84cda87a260a42108f1ef6c4767c174bc8b1fb61
Reviewed-on: https://chromium-review.googlesource.com/c/1356813Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: Ivan Šandrk <isandrk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#613254}

chrome/browser/extensions/api/tabs/tabs_api.cc

@@ -100,6 +100,7 @@
 #include "ash/public/cpp/window_pin_type.h"
 #include "ash/public/cpp/window_properties.h"
 #include "ash/public/interfaces/window_pin_type.mojom.h"
+#include "chrome/browser/chromeos/arc/arc_util.h"
 #include "chrome/browser/ui/ash/chrome_screenshot_grabber.h"
 #include "chrome/browser/ui/browser_command_controller.h"
 #include "content/public/browser/devtools_agent_host.h"
@@ -312,6 +313,11 @@ void SetLockedFullscreenState(Browser* browser, bool locked) {
   // fullscreen (security concerns).
   ui::Clipboard::GetForCurrentThread()->Clear(ui::CLIPBOARD_TYPE_COPY_PASTE);
   content::DevToolsAgentHost::DetachAllClients();
+
+  // Disable ARC while in the locked fullscreen mode.
+  Profile* const profile = browser->profile();
+  if (arc::IsArcAllowedForProfile(profile))
+    arc::SetArcPlayStoreEnabledForProfile(profile, !locked);
 }
 
 #endif  // defined(OS_CHROMEOS)