Update {virtual,override} to follow C++11 style in ppapi.

The Google style guide states that only one of {virtual,override,final} should be used for each declaration, since override implies virtual and final implies both virtual and override.

This patch was manually generated using a regex and a text editor.

BUG=417463

Review URL: https://codereview.chromium.org/1097393007

Cr-Commit-Position: refs/heads/master@{#326505}
diff --git a/ppapi/proxy/plugin_resource.h b/ppapi/proxy/plugin_resource.h
index fd905cf..0f21240 100644
--- a/ppapi/proxy/plugin_resource.h
+++ b/ppapi/proxy/plugin_resource.h
@@ -34,7 +34,7 @@
   };
 
   PluginResource(Connection connection, PP_Instance instance);
-  virtual ~PluginResource();
+  ~PluginResource() override;
 
   // Returns true if we've previously sent a create message to the browser
   // or renderer. Generally resources will use these to tell if they should
@@ -45,16 +45,15 @@
   // This handles a reply to a resource call. It works by looking up the
   // callback that was registered when CallBrowser/CallRenderer was called
   // and calling it with |params| and |msg|.
-  virtual void OnReplyReceived(const proxy::ResourceMessageReplyParams& params,
-                               const IPC::Message& msg) override;
+  void OnReplyReceived(const proxy::ResourceMessageReplyParams& params,
+                       const IPC::Message& msg) override;
 
   // Resource overrides.
   // Note: Subclasses shouldn't override these methods directly. Instead, they
   // should implement LastPluginRefWasDeleted() or InstanceWasDeleted() to get
   // notified.
-  virtual void NotifyLastPluginRefWasDeleted() override;
-  virtual void NotifyInstanceWasDeleted() override;
-
+  void NotifyLastPluginRefWasDeleted() override;
+  void NotifyInstanceWasDeleted() override;
 
   // Sends a create message to the browser or renderer for the current resource.
   void SendCreate(Destination dest, const IPC::Message& msg);