aura: Avoid resizing when dragging top of browser frame.

This makes BrowserNonClientFrameViewAura act as if it has a
zero-height top resize border to avoid weird resizing when
dragging that region up or down.  In the longer term, this
change should be reverted and the Aura shell should instead
be responsible for disabling resizes (and preventing the
cursor from changing as well, I suppose).

BUG=101830
TEST=manual: checked that dragging the top of the frame only moves the window instead of resizing it

Review URL: http://codereview.chromium.org/8400011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@107579 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/views/frame/browser_non_client_frame_view_aura.cc

@@ -237,8 +237,10 @@ int BrowserNonClientFrameViewAura::NonClientHitTestImpl(
 
   // Test window resize components.
   bool can_resize = GetWidget()->widget_delegate()->CanResize();
+  // TODO(derat): Disallow resizing via the top border in the Aura shell
+  // instead of enforcing it here.  See http://crbug.com/101830.
   frame_component = GetHTComponentForFrame(point,
-                                           kResizeBorderThickness,
+                                           0,
                                            kResizeBorderThickness,
                                            kResizeBorderThickness,
                                            kResizeBorderThickness,