Revert of [blink] Unique pointers in Platform.h

ui/events/blink/input_handler_proxy_unittest.cc

Index: ui/events/blink/input_handler_proxy_unittest.cc
diff --git a/ui/events/blink/input_handler_proxy_unittest.cc b/ui/events/blink/input_handler_proxy_unittest.cc
index 10ac7586404002afe6bc618f6866439b31c4f057..e30d729e3618c57ebcaffcc049a98b5caa21c336 100644
--- a/ui/events/blink/input_handler_proxy_unittest.cc
+++ b/ui/events/blink/input_handler_proxy_unittest.cc
@@ -296,11 +296,11 @@
     DispatchNonBlockingEventToMainThread_(*event.get());
   }
 
-  std::unique_ptr<blink::WebGestureCurve> CreateFlingAnimationCurve(
+  blink::WebGestureCurve* CreateFlingAnimationCurve(
       WebGestureDevice deviceSource,
       const WebFloatPoint& velocity,
       const WebSize& cumulative_scroll) override {
-    return base::MakeUnique<FakeWebGestureCurve>(
+    return new FakeWebGestureCurve(
         blink::WebFloatSize(velocity.x, velocity.y),
         blink::WebFloatSize(cumulative_scroll.width, cumulative_scroll.height));
   }