Mojo: Convert OVERRIDE -> override in various subdirectories of mojo/.

mojo/embedder/platform_channel_pair_posix_unittest.cc

Index: mojo/embedder/platform_channel_pair_posix_unittest.cc
diff --git a/mojo/embedder/platform_channel_pair_posix_unittest.cc b/mojo/embedder/platform_channel_pair_posix_unittest.cc
index 523b7676a5c43da2cc9f120d8e4881ef1546e667..b3f9682dc687c2a5877f6e16a4905f645738ff35 100644
--- a/mojo/embedder/platform_channel_pair_posix_unittest.cc
+++ b/mojo/embedder/platform_channel_pair_posix_unittest.cc
@@ -44,14 +44,14 @@ class PlatformChannelPairPosixTest : public testing::Test {
   PlatformChannelPairPosixTest() {}
   virtual ~PlatformChannelPairPosixTest() {}
 
-  virtual void SetUp() OVERRIDE {
+  virtual void SetUp() override {
     // Make sure |SIGPIPE| isn't being ignored.
     struct sigaction action = {};
     action.sa_handler = SIG_DFL;
     ASSERT_EQ(0, sigaction(SIGPIPE, &action, &old_action_));
   }
 
-  virtual void TearDown() OVERRIDE {
+  virtual void TearDown() override {
     // Restore the |SIGPIPE| handler.
     ASSERT_EQ(0, sigaction(SIGPIPE, &old_action_, nullptr));
   }