Fix grammatical errors in comments in ui/views

ui/views/widget/widget.h

 // Copyright (c) 2012 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 UI_VIEWS_WIDGET_WIDGET_H_
 #define UI_VIEWS_WIDGET_WIDGET_H_
 #pragma once
 
 #include <set>
 #include <stack>
@@ skipping 126 matching lines @@
       // destroyed.
       NATIVE_WIDGET_OWNS_WIDGET,
       // Used when the Widget is owned by someone other than the NativeWidget,
       // e.g. a scoped_ptr in tests.
       WIDGET_OWNS_NATIVE_WIDGET
     };
 
     InitParams();
     explicit InitParams(Type type);
 
-    // If |parent_widget| is non-null, it's native view is returned, otherwise
+    // If |parent_widget| is non-null, its native view is returned, otherwise
     // |parent| is returned.
     gfx::NativeView GetParent() const;
 
     Type type;
     // If NULL, a default implementation will be constructed.
     WidgetDelegate* delegate;
     bool child;
     bool transient;
     // If true, the widget may be fully or partially transparent.  If false,
     // we can perform optimizations based on the widget being fully opaque.
@@ skipping 621 matching lines @@
   // duplicate move events even though the mouse hasn't moved.
   bool last_mouse_event_was_move_;
   gfx::Point last_mouse_event_position_;
 
   DISALLOW_COPY_AND_ASSIGN(Widget);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_WIDGET_H_