[Mac][Material Design] Fix TabStripController test that fails under MD.

chrome/browser/ui/cocoa/tabs/tab_strip_controller_unittest.mm

 // 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.
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/bind_helpers.h"
 #include "base/mac/scoped_nsautorelease_pool.h"
 #include "chrome/browser/media/media_capture_devices_dispatcher.h"
 #include "chrome/browser/media/media_stream_capture_indicator.h"
@@ skipping 232 matching lines @@
   TabView* tab2 = CreateTab();
 
   EXPECT_FALSE([tab1 controller].selected);
   EXPECT_TRUE([tab2 controller].selected);
 
   // Check that there's no hovered tab yet.
   EXPECT_FALSE([controller_ hoveredTab]);
 
   // Set up mouse event on overlap of tab1 + tab2.
   const CGFloat min_y = NSMinY([tab_strip_.get() frame]) + 1;
+  const CGFloat tab_overlap = [TabStripController tabOverlap];
 
   // Hover over overlap between tab 1 and 2.
-  NSEvent* event =
-      cocoa_test_event_utils::MouseEventAtPoint(NSMakePoint(280, min_y),
-                                                NSMouseMoved, 0);
+  NSRect tab1_frame = [tab1 frame];
+  NSPoint tab_overlap_point =
+      NSMakePoint(NSMaxX(tab1_frame) - tab_overlap / 2, min_y);
+
+  NSEvent* event = cocoa_test_event_utils::MouseEventAtPoint(tab_overlap_point,
+                                                             NSMouseMoved,
+                                                             0);
   [controller_.get() mouseMoved:event];
   EXPECT_EQ(tab2, [controller_ hoveredTab]);
 
   // Hover over tab 1.
-  event = cocoa_test_event_utils::MouseEventAtPoint(NSMakePoint(260, min_y),
-                                                    NSMouseMoved, 0);
+  NSPoint hover_point = NSMakePoint(NSMidX(tab1_frame), min_y);
+  event =
+      cocoa_test_event_utils::MouseEventAtPoint(hover_point, NSMouseMoved, 0);
   [controller_.get() mouseMoved:event];
   EXPECT_EQ(tab1, [controller_ hoveredTab]);
 
   // Hover over tab 2.
-  event = cocoa_test_event_utils::MouseEventAtPoint(NSMakePoint(290, min_y),
-                                                    NSMouseMoved, 0);
+  NSRect tab2_frame = [tab2 frame];
+  hover_point = NSMakePoint(NSMidX(tab2_frame), min_y);
+  event =
+      cocoa_test_event_utils::MouseEventAtPoint(hover_point, NSMouseMoved, 0);
   [controller_.get() mouseMoved:event];
   EXPECT_EQ(tab2, [controller_ hoveredTab]);
 }
 
 TEST_F(TabStripControllerTest, CorrectTitleAndToolTipTextFromSetTabTitle) {
   using content::MediaStreamDevice;
   using content::MediaStreamDevices;
   using content::MediaStreamUI;
 
   TabView* const tab = CreateTab();
@@ skipping 196 matching lines @@
   [tabStripControllerForTesting setAlertStateForContents:contents_at_tab0
                                           withAlertState:TabAlertState::NONE];
   [controller_ updateWindowAlertState:TabAlertState::NONE
                        forWebContents:contents_at_tab0];
   // Neither of tabs playing nor muting, so the window alert state should be
   // NONE.
   EXPECT_EQ(TabAlertState::NONE, [window_controller alertState]);
 }
 
 }  // namespace