Update plugin to handle new style rules for virtual annotations.

tools/clang/plugins/tests/virtual_specifiers.txt

Index: tools/clang/plugins/tests/virtual_specifiers.txt
diff --git a/tools/clang/plugins/tests/virtual_specifiers.txt b/tools/clang/plugins/tests/virtual_specifiers.txt
new file mode 100644
index 0000000000000000000000000000000000000000..2ad1420ba03435cfa26a70f43bcfcca0fd9e8cd6
--- /dev/null
+++ b/tools/clang/plugins/tests/virtual_specifiers.txt
@@ -0,0 +1,51 @@
+virtual_specifiers.cpp:36:21: warning: [chromium-style] Overriding method must be marked with 'override' or 'final'.
+  ~MissingOverride() {}
+                    ^
+                     override
+virtual_specifiers.cpp:37:11: warning: [chromium-style] Overriding method must be marked with 'override' or 'final'.
+  void F() {}
+          ^
+           override
+virtual_specifiers.cpp:43:3: warning: [chromium-style] 'virtual' is redundant; 'override' implies 'virtual'.
+  virtual ~VirtualAndOverride() OVERRIDE {}
+  ^~~~~~~~
+virtual_specifiers.cpp:44:3: warning: [chromium-style] 'virtual' is redundant; 'override' implies 'virtual'.
+  virtual void F() OVERRIDE {}
+  ^~~~~~~~
+virtual_specifiers.cpp:49:3: warning: [chromium-style] 'virtual' is redundant; 'final' implies 'virtual'.
+  virtual ~VirtualAndFinal() FINAL {}
+  ^~~~~~~~
+virtual_specifiers.cpp:50:3: warning: [chromium-style] 'virtual' is redundant; 'final' implies 'virtual'.
+  virtual void F() FINAL {}
+  ^~~~~~~~
+virtual_specifiers.cpp:55:3: warning: [chromium-style] 'virtual' is redundant; 'override' implies 'virtual'.
+  virtual ~VirtualAndOverrideFinal() OVERRIDE FINAL {}
+  ^~~~~~~~
+virtual_specifiers.cpp:55:38: warning: [chromium-style] 'override' is redundant; 'final' implies 'override'.
+  virtual ~VirtualAndOverrideFinal() OVERRIDE FINAL {}
+                                     ^~~~~~~~~
+virtual_specifiers.cpp:10:18: note: expanded from macro 'OVERRIDE'
+#define OVERRIDE override
+                 ^
+virtual_specifiers.cpp:56:3: warning: [chromium-style] 'virtual' is redundant; 'override' implies 'virtual'.
+  virtual void F() OVERRIDE FINAL {}
+  ^~~~~~~~
+virtual_specifiers.cpp:56:20: warning: [chromium-style] 'override' is redundant; 'final' implies 'override'.
+  virtual void F() OVERRIDE FINAL {}
+                   ^~~~~~~~~
+virtual_specifiers.cpp:10:18: note: expanded from macro 'OVERRIDE'
+#define OVERRIDE override
+                 ^
+virtual_specifiers.cpp:61:23: warning: [chromium-style] 'override' is redundant; 'final' implies 'override'.
+  ~OverrideAndFinal() OVERRIDE FINAL {}
+                      ^~~~~~~~~
+virtual_specifiers.cpp:10:18: note: expanded from macro 'OVERRIDE'
+#define OVERRIDE override
+                 ^
+virtual_specifiers.cpp:62:12: warning: [chromium-style] 'override' is redundant; 'final' implies 'override'.
+  void F() OVERRIDE FINAL {}
+           ^~~~~~~~~
+virtual_specifiers.cpp:10:18: note: expanded from macro 'OVERRIDE'
+#define OVERRIDE override
+                 ^
+12 warnings generated.