Remove opaque-frame-only code to reduce top resize border size by 1 px.

chrome/browser/ui/views/frame/opaque_browser_frame_view.h

Index: chrome/browser/ui/views/frame/opaque_browser_frame_view.h
diff --git a/chrome/browser/ui/views/frame/opaque_browser_frame_view.h b/chrome/browser/ui/views/frame/opaque_browser_frame_view.h
index 41632a7837778e9d8fc8f43c3c6a9eda07fb06b5..8048bb5d7e2ebe24af6dd4eaff20c39d5d4ee74c 100644
--- a/chrome/browser/ui/views/frame/opaque_browser_frame_view.h
+++ b/chrome/browser/ui/views/frame/opaque_browser_frame_view.h
@@ -120,10 +120,6 @@ class OpaqueBrowserFrameView : public BrowserNonClientFrameView,
   // calculated as if the window was restored, regardless of its current state.
   int FrameBorderThickness(bool restored) const;
 
-  // Returns the height of the top resize area.  This is smaller than the frame
-  // border height in order to increase the window draggable area.
-  int TopResizeHeight() const;
-
   // Returns true if the specified point is within the avatar menu buttons.
   bool IsWithinAvatarMenuButtons(const gfx::Point& point) const;