Alternate NTP Mac: Push down overlay in presentation mode

chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller_browsertest.mm

 // Copyright 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.
 
 #import "chrome/browser/ui/cocoa/tab_contents/overlayable_contents_controller.h"
 
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/cocoa/browser_window_controller.h"
@@ skipping 154 matching lines @@
   mode.mode = SearchMode::MODE_SEARCH_SUGGESTIONS;
   instant_overlay_model_.SetOverlayState(mode, 10, INSTANT_SIZE_PERCENT);
 
   registrar_.Add(this,
                  content::NOTIFICATION_WEB_CONTENTS_VISIBILITY_CHANGED,
                  content::Source<content::WebContents>(web_contents_.get()));
   EXPECT_EQ(0, visibility_changed_count_);
   instant_overlay_model_.SetOverlayState(mode, 11, INSTANT_SIZE_PERCENT);
   EXPECT_EQ(1, visibility_changed_count_);
 }
+
+IN_PROC_BROWSER_TEST_F(OverlayableContentsControllerTest, OverlayOffset) {
+  SearchMode mode;
+  mode.mode = SearchMode::MODE_NTP;
+  CGFloat expected_height = 10;
+  InstantSizeUnits units = INSTANT_SIZE_PIXELS;
+  instant_overlay_model_.SetOverlayState(mode, expected_height, units);
+
+  CGFloat separator_height = [OverlayTopSeparatorView preferredHeight];
+  NSView* overlay_view = web_contents_->GetView()->GetNativeView();
+  EXPECT_EQ(separator_height,
+            NSMaxY([[overlay_view superview] frame]) -
+            NSMaxY([overlay_view frame]));
+
+  CGFloat offset = 30;
+  [controller_ setOverlayContentsOffset:offset];
+  EXPECT_EQ(separator_height + offset,
+            NSMaxY([[overlay_view superview] frame]) -
+            NSMaxY([overlay_view frame]));
+}