Explicitly coerce PostDispatchAction to uint32_t in DispatchEvent()

ui/aura/window_tree_host_x11.cc

Index: ui/aura/window_tree_host_x11.cc
diff --git a/ui/aura/window_tree_host_x11.cc b/ui/aura/window_tree_host_x11.cc
index 06c3a3f381c92b8533ba5c4d52f05d6f08b2ae1b..861893c1312c2435d65f5f9c287717c8beaa83bd 100644
--- a/ui/aura/window_tree_host_x11.cc
+++ b/ui/aura/window_tree_host_x11.cc
@@ -325,7 +325,7 @@ uint32_t WindowTreeHostX11::DispatchEvent(const ui::PlatformEvent& event) {
   if (FindEventTarget(xev) == x_root_window_) {
     if (xev->type == GenericEvent)
       DispatchXI2Event(xev);
-    return ui::POST_DISPATCH_NONE;
+    return ui::kPostDispatchNone;
   }
 
   if (xev->type == MotionNotify) {
@@ -353,7 +353,7 @@ uint32_t WindowTreeHostX11::DispatchEvent(const ui::PlatformEvent& event) {
     // NativeViewGLSurfaceGLX adds a child to |xwindow_|.
     // TODO(pkotwicz|tdanderson): Figure out whether the suppression is
     // necessary. crbug.com/385716
-    return ui::POST_DISPATCH_STOP_PROPAGATION;
+    return ui::kPostDispatchStopPropagation;
   }
 
   if (xev->type == EnterNotify ||
@@ -405,7 +405,7 @@ uint32_t WindowTreeHostX11::DispatchEvent(const ui::PlatformEvent& event) {
       default:
          NOTREACHED();
     }
-    return ui::POST_DISPATCH_STOP_PROPAGATION;
+    return ui::kPostDispatchStopPropagation;
   }
 
   switch (xev->type) {
@@ -474,7 +474,7 @@ uint32_t WindowTreeHostX11::DispatchEvent(const ui::PlatformEvent& event) {
       break;
     }
   }
-  return ui::POST_DISPATCH_STOP_PROPAGATION;
+  return ui::kPostDispatchStopPropagation;
 }
 
 ui::EventSource* WindowTreeHostX11::GetEventSource() {