Standardize usage of virtual/override/final specifiers.

media/filters/ffmpeg_glue_unittest.cc

Index: media/filters/ffmpeg_glue_unittest.cc
diff --git a/media/filters/ffmpeg_glue_unittest.cc b/media/filters/ffmpeg_glue_unittest.cc
index 605b3194a16ddff3c3c14026350c1ab75e1e2d22..f9cfda5a646bac28066a65b5afc8088cfcd72e67 100644
--- a/media/filters/ffmpeg_glue_unittest.cc
+++ b/media/filters/ffmpeg_glue_unittest.cc
@@ -45,7 +45,7 @@ class FFmpegGlueTest : public ::testing::Test {
     CHECK(glue_->format_context()->pb);
   }
 
-  virtual ~FFmpegGlueTest() {
+  ~FFmpegGlueTest() override {
     // Ensure |glue_| and |protocol_| are still alive.
     CHECK(glue_.get());
     CHECK(protocol_.get());
@@ -84,7 +84,7 @@ class FFmpegGlueDestructionTest : public ::testing::Test {
     CHECK(glue_->format_context()->pb);
   }
 
-  virtual ~FFmpegGlueDestructionTest() {
+  ~FFmpegGlueDestructionTest() override {
     // Ensure Initialize() was called.
     CHECK(glue_.get());
     CHECK(protocol_.get());