Refactored GlassBrowserFrameView and BrowserDesktopTreeHostWin.

chrome/browser/ui/views/frame/opaque_browser_frame_view.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 CHROME_BROWSER_UI_VIEWS_FRAME_OPAQUE_BROWSER_FRAME_VIEW_H_
 #define CHROME_BROWSER_UI_VIEWS_FRAME_OPAQUE_BROWSER_FRAME_VIEW_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/ui/view_ids.h"
@@ skipping 108 matching lines @@
                                               ViewID view_id);
 
   // Returns the thickness of the border that makes up the window frame edges.
   // This does not include any client edge.  If |restored| is true, this is
   // calculated as if the window was restored, regardless of its current state.
   int FrameBorderThickness(bool restored) const;
 
   // Returns true if the specified point is within the avatar menu buttons.
   bool IsWithinAvatarMenuButtons(const gfx::Point& point) const;
 
-  // Returns the thickness of the entire nonclient left, right, and bottom
-  // borders, including both the window frame and any client edge.
+  // Returns the thickness of the entire nonclient left, right, top, and bottom
+  // borders, including both the window frame and any client edge, but excluding
+  // the titlebar/tabstrip area.

[Peter Kasting, 2016/04/15 00:20:52]

Now I'm really confused -- I don't know what "the entire nonclient top border,
but excluding the titlebar/tabstrip area" actually includes.

And I don't think this is ever used for a top border height, nor would it be
accurate for that (since, even excluding the titlebar/tabstrip, there's no
client edge on the top border).

So it seems like the old comment was more correct.

[Bret, 2016/04/15 23:07:08]

Hmmm okay you're right, this was the same mistake as the corner width comment
edit I made in the other file, I mixed up how the parameters of
GetHTComponentForFrame are used. Anyway, reverted.

   int NonClientBorderThickness() const;
 
   // Returns the bounds of the titlebar icon (or where the icon would be if
   // there was one).
   gfx::Rect IconBounds() const;
 
   // Returns true if the view should draw its own custom title bar.
   bool ShouldShowWindowTitleBar() const;
 
   // Computes the height of the top area of the frame.
@@ skipping 33 matching lines @@
   // Background painter for the window frame.
   scoped_ptr<views::FrameBackground> frame_background_;
 
   // Observer that handles platform dependent configuration.
   scoped_ptr<OpaqueBrowserFrameViewPlatformSpecific> platform_observer_;
 
   DISALLOW_COPY_AND_ASSIGN(OpaqueBrowserFrameView);
 };
 
 #endif  // CHROME_BROWSER_UI_VIEWS_FRAME_OPAQUE_BROWSER_FRAME_VIEW_H_