Make Time functions go through the Platform layer.

src/default-platform.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 25 matching lines @@
 class DefaultPlatform : public Platform {
  public:
   DefaultPlatform();
   virtual ~DefaultPlatform();
 
   // v8::Platform implementation.
   virtual void CallOnBackgroundThread(
       Task *task, ExpectedRuntime expected_runtime) V8_OVERRIDE;
   virtual void CallOnForegroundThread(v8::Isolate *isolate,
                                       Task *task) V8_OVERRIDE;
+  virtual int64_t CurrentTime() V8_OVERRIDE;
+  virtual int64_t CurrentTimeFromSystemTime() V8_OVERRIDE;
+  virtual int64_t TimeTicksNow() V8_OVERRIDE;
+  virtual int64_t TimeTicksHighResNow() V8_OVERRIDE;
+  virtual bool TimeTicksHasHighRes() V8_OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DefaultPlatform);
 };
 
 
 } }  // namespace v8::internal
 
 
 #endif  // V8_DEFAULT_PLATFORM_H_