Make the header/content separator into a hairline for apps in hidpi

ash/frame/custom_frame_view_ash_unittest.cc

 // 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.
 
 #include "ash/frame/custom_frame_view_ash.h"
 
 #include "ash/test/ash_test_base.h"
 #include "base/memory/scoped_ptr.h"
 #include "grit/ash_resources.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 95 matching lines @@
 TEST_F(CustomFrameViewAshTest, HeaderHeight) {
   TestWidgetDelegate* delegate = new TestWidgetDelegate;
 
   scoped_ptr<views::Widget> widget(CreateWidget(delegate));
   widget->Show();
 
   ui::ResourceBundle& rb = ui::ResourceBundle::GetSharedInstance();
   gfx::ImageSkia* close_button =
       rb.GetImageSkiaNamed(IDR_AURA_WINDOW_CONTROL_BACKGROUND_H);
 
-  // |kSeparatorSize| should match |kHeaderContentSeparatorSize| in
-  // default_header_painter.cc
-  // TODO(pkotwicz): Clean this test up once the separator overlays the window
-  // controls.
-  const int kSeparatorSize = 1;
-
-  // The header should have enough room for the window controls and the
-  // separator line.
-  EXPECT_EQ(close_button->height() + kSeparatorSize,
-            delegate->custom_frame_view()->GetHeaderView()->height());
-
-  widget->Maximize();
-  EXPECT_EQ(close_button->height() + kSeparatorSize,
+  // The header should have enough room for the window controls. The
+  // header/content separator line overlays the window controls.
+  EXPECT_EQ(close_button->height(),
             delegate->custom_frame_view()->GetHeaderView()->height());
 }
 
 // Verify that CustomFrameViewAsh returns the correct minimum and maximum frame
 // sizes when the client view does not specify any size constraints.
 TEST_F(CustomFrameViewAshTest, NoSizeConstraints) {
   TestWidgetConstraintsDelegate* delegate = new TestWidgetConstraintsDelegate;
   scoped_ptr<views::Widget> widget(CreateWidget(delegate));
 
   CustomFrameViewAsh* custom_frame_view = delegate->custom_frame_view();
@@ skipping 23 matching lines @@
 
   EXPECT_EQ(min_client_size.width(), min_frame_size.width());
   EXPECT_EQ(max_client_size.width(), max_frame_size.width());
   EXPECT_EQ(min_client_size.height() + delegate->GetTitleBarHeight(),
             min_frame_size.height());
   EXPECT_EQ(max_client_size.height() + delegate->GetTitleBarHeight(),
             max_frame_size.height());
 }
 
 }  // namespace ash