events: Change gesture-event handler in EventHandler to not return any values.

ui/views/controls/scrollbar/base_scroll_bar.cc

Index: ui/views/controls/scrollbar/base_scroll_bar.cc
diff --git a/ui/views/controls/scrollbar/base_scroll_bar.cc b/ui/views/controls/scrollbar/base_scroll_bar.cc
index 833ac7983e9295e27318225aa91728e4351d15ed..6643735b5ce83fab6b67059c8b90d69cef4b9845 100644
--- a/ui/views/controls/scrollbar/base_scroll_bar.cc
+++ b/ui/views/controls/scrollbar/base_scroll_bar.cc
@@ -172,7 +172,7 @@ bool BaseScrollBar::OnMouseWheel(const ui::MouseWheelEvent& event) {
   return true;
 }
 
-ui::EventResult BaseScrollBar::OnGestureEvent(ui::GestureEvent* event) {
+void BaseScrollBar::OnGestureEvent(ui::GestureEvent* event) {
   // If a fling is in progress, then stop the fling for any incoming gesture
   // event (except for the GESTURE_END event that is generated at the end of the
   // fling).
@@ -184,13 +184,14 @@ ui::EventResult BaseScrollBar::OnGestureEvent(ui::GestureEvent* event) {
 
   if (event->type() == ui::ET_GESTURE_TAP_DOWN) {
     ProcessPressEvent(*event);
-    return ui::ER_CONSUMED;
+    event->SetHandled();
+    return;
   }
 
   if (event->type() == ui::ET_GESTURE_LONG_PRESS) {
     // For a long-press, the repeater started in tap-down should continue. So
     // return early.
-    return ui::ER_UNHANDLED;
+    return;
   }
 
   ResetState();
@@ -198,17 +199,21 @@ ui::EventResult BaseScrollBar::OnGestureEvent(ui::GestureEvent* event) {
   if (event->type() == ui::ET_GESTURE_TAP) {
     // TAP_DOWN would have already scrolled some amount. So scrolling again on
     // TAP is not necessary.
-    return ui::ER_CONSUMED;
+    event->SetHandled();
+    return;
   }
 
   if (event->type() == ui::ET_GESTURE_SCROLL_BEGIN ||
-      event->type() == ui::ET_GESTURE_SCROLL_END)
-    return ui::ER_CONSUMED;
+      event->type() == ui::ET_GESTURE_SCROLL_END) {
+    event->SetHandled();
+    return;
+  }
 
   if (event->type() == ui::ET_GESTURE_SCROLL_UPDATE) {
     ScrollByContentsOffset(IsHorizontal() ? event->details().scroll_x() :
                                             event->details().scroll_y());
-    return ui::ER_CONSUMED;
+    event->SetHandled();
+    return;
   }
 
   if (event->type() == ui::ET_SCROLL_FLING_START) {
@@ -217,10 +222,8 @@ ui::EventResult BaseScrollBar::OnGestureEvent(ui::GestureEvent* event) {
     scroll_animator_->Start(
         IsHorizontal() ?  event->details().velocity_x() : 0.f,
         IsHorizontal() ? 0.f : event->details().velocity_y());
-    return ui::ER_CONSUMED;
+    event->SetHandled();
   }
-
-  return ui::ER_UNHANDLED;
 }
 
 ///////////////////////////////////////////////////////////////////////////////