Add constructors to WebInputEvents and setters so we can work at cleaning up these public structs.

blimp/engine/feature/engine_render_widget_feature_unittest.cc

Index: blimp/engine/feature/engine_render_widget_feature_unittest.cc
diff --git a/blimp/engine/feature/engine_render_widget_feature_unittest.cc b/blimp/engine/feature/engine_render_widget_feature_unittest.cc
index e93ab78f556f82d8dad8603346dad6286374cc39..9f8ed87edfa01a6067ebd60d23795a24f2d177a5 100644
--- a/blimp/engine/feature/engine_render_widget_feature_unittest.cc
+++ b/blimp/engine/feature/engine_render_widget_feature_unittest.cc
@@ -163,8 +163,9 @@ MATCHER_P5(BlimpImeMsgEquals,
 void SendInputMessage(BlimpMessageProcessor* processor,
                       int tab_id,
                       int rw_id) {
-  blink::WebGestureEvent input_event;
-  input_event.type = blink::WebGestureEvent::Type::GestureTap;
+  blink::WebGestureEvent input_event(blink::WebGestureEvent::Type::GestureTap,
+                                     blink::WebInputEvent::NoModifiers,
+                                     blink::WebInputEvent::TimeStampForTesting);
 
   InputMessageGenerator generator;
   std::unique_ptr<BlimpMessage> message =