Add implementation of MonotonicallyIncreasingTime to Gin's V8 platform implementation.

gin/public/v8_platform.h

Index: gin/public/v8_platform.h
diff --git a/gin/public/v8_platform.h b/gin/public/v8_platform.h
index 2df0f848e599e99ffd7ffd53511b4d8fc354d3ca..f085b58ecfbfd3c403e33c7143118733f831c914 100644
--- a/gin/public/v8_platform.h
+++ b/gin/public/v8_platform.h
@@ -24,6 +24,7 @@ class GIN_EXPORT V8Platform : public NON_EXPORTED_BASE(v8::Platform) {
       v8::Platform::ExpectedRuntime expected_runtime) OVERRIDE;
   virtual void CallOnForegroundThread(v8::Isolate* isolate,
                                       v8::Task* task) OVERRIDE;
+  virtual double MonotonicallyIncreasingTime() OVERRIDE;
  private:
   friend struct base::DefaultLazyInstanceTraits<V8Platform>;