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

chrome/browser/cocoa/accelerators_cocoa_unittest.mm

Index: chrome/browser/cocoa/accelerators_cocoa_unittest.mm
diff --git a/chrome/browser/cocoa/accelerators_cocoa_unittest.mm b/chrome/browser/cocoa/accelerators_cocoa_unittest.mm
index cac5c200ddd3ba0f90f9083d58ed6b128c6c74e0..28b99865a49de32dc965e167866ddc257efad099 100644
--- a/chrome/browser/cocoa/accelerators_cocoa_unittest.mm
+++ b/chrome/browser/cocoa/accelerators_cocoa_unittest.mm
@@ -9,13 +9,14 @@
 #include "chrome/app/chrome_dll_resource.h"
 #import "chrome/browser/cocoa/accelerators_cocoa.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "testing/gtest_mac.h"
 
 TEST(AcceleratorsCocoaTest, GetAccelerator) {
   AcceleratorsCocoa* keymap = Singleton<AcceleratorsCocoa>::get();
   const menus::AcceleratorCocoa* accelerator =
       keymap->GetAcceleratorForCommand(IDC_COPY);
   ASSERT_TRUE(accelerator);
-  EXPECT_TRUE([@"c" isEqualToString:accelerator->characters()]);
+  EXPECT_NSEQ(@"c", accelerator->characters());
   EXPECT_EQ(NSCommandKeyMask, accelerator->modifiers());
 }