[Mac] Use the new {EXPECT,ASSERT}_NS{EQ,NE} macros where possible.

chrome/browser/cocoa/tab_controller_unittest.mm

Index: chrome/browser/cocoa/tab_controller_unittest.mm
diff --git a/chrome/browser/cocoa/tab_controller_unittest.mm b/chrome/browser/cocoa/tab_controller_unittest.mm
index 16f527c2393b18107b7228eaf734fc36ec5ba257..51f453e79f542ed0544ebf25d707615e5eaa4304 100644
--- a/chrome/browser/cocoa/tab_controller_unittest.mm
+++ b/chrome/browser/cocoa/tab_controller_unittest.mm
@@ -9,6 +9,7 @@
 #import "chrome/browser/cocoa/tab_controller_target.h"
 #include "chrome/browser/cocoa/cocoa_test_helper.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#import "testing/gtest_mac.h"
 #include "testing/platform_test.h"
 
 // Implements the target interface for the tab, which gets sent messages when
@@ -121,7 +122,7 @@ TEST_F(TabControllerTest, ToolTip) {
   EXPECT_TRUE([[controller toolTip] length] == 0);
   NSString *tooltip_string = @"Some text to use as a tab title";
   [controller setTitle:tooltip_string];
-  EXPECT_TRUE([tooltip_string isEqualToString:[controller toolTip]]);
+  EXPECT_NSEQ(tooltip_string, [controller toolTip]);
 }
 
 // Tests setting the |loading| property via code.