Standardize usage of virtual/override/final specifiers.

components/crash/app/breakpad_linux.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // For linux_syscall_support.h. This makes it safe to call embedded system
 // calls when in seccomp mode.
 
 #include "components/crash/app/breakpad_linux.h"
 
 #include <fcntl.h>
@@ skipping 739 matching lines @@
 }
 #else
 // Non-Browser = Extension, Gpu, Plugins, Ppapi and Renderer
 class NonBrowserCrashHandler : public google_breakpad::CrashGenerationClient {
  public:
   NonBrowserCrashHandler()
       : server_fd_(base::GlobalDescriptors::GetInstance()->Get(
             kCrashDumpSignal)) {
   }
 
-  virtual ~NonBrowserCrashHandler() {}
+  ~NonBrowserCrashHandler() override {}
 
-  virtual bool RequestDump(const void* crash_context,
-                           size_t crash_context_size) override {
+  bool RequestDump(const void* crash_context,
+                   size_t crash_context_size) override {
     int fds[2] = { -1, -1 };
     if (sys_socketpair(AF_UNIX, SOCK_STREAM, 0, fds) < 0) {
       static const char msg[] = "Failed to create socket for crash dumping.\n";
       WriteLog(msg, sizeof(msg) - 1);
       return false;
     }
 
     // Start constructing the message to send to the browser.
     char b;  // Dummy variable for sys_read below.
     const char* b_addr = &b;  // Get the address of |b| so we can create the
@@ skipping 865 matching lines @@
     }
   }
 }
 #endif  // OS_ANDROID
 
 bool IsCrashReporterEnabled() {
   return g_is_crash_reporter_enabled;
 }
 
 }  // namespace breakpad