Permission prompts show in the top-left corner in fullscreen mode.

chrome/browser/ui/views/website_settings/permissions_bubble_view.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_UI_VIEWS_WEBSITE_SETTINGS_PERMISSIONS_BUBBLE_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_WEBSITE_SETTINGS_PERMISSIONS_BUBBLE_VIEW_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 26 matching lines @@
   gfx::NativeWindow GetNativeWindow() override;
 
   void Closing();
   void Toggle(int index, bool value);
   void Accept();
   void Deny();
 
  private:
   // These three functions have separate implementations for Views-based and
   // Cocoa-based browsers, to allow this bubble to be used in either.
+
+  // Returns the view to anchor the permission bubble to. May be null.
   views::View* GetAnchorView();
+  // Returns the anchor point to anchor the permission bubble to, as a fallback.
+  // Only used if GetAnchorView() returns nullptr.
   gfx::Point GetAnchorPoint();
+  // Returns the type of arrow to display on the permission bubble.
   views::BubbleBorder::Arrow GetAnchorArrow();
 
   Browser* browser_;
   Delegate* delegate_;
   PermissionsBubbleDialogDelegateView* bubble_delegate_;
 
   DISALLOW_COPY_AND_ASSIGN(PermissionBubbleViewViews);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_WEBSITE_SETTINGS_PERMISSIONS_BUBBLE_VIEW_H_