Fix an interactive ui test

ui/aura/test/ui_controls_factory_ozone.cc

Index: ui/aura/test/ui_controls_factory_ozone.cc
diff --git a/ui/aura/test/ui_controls_factory_ozone.cc b/ui/aura/test/ui_controls_factory_ozone.cc
index 403757b947503c7c2cf344760960eb90af5a6937..cc3589e4778bbc6d7d27b45374e40899a740ffec 100644
--- a/ui/aura/test/ui_controls_factory_ozone.cc
+++ b/ui/aura/test/ui_controls_factory_ozone.cc
@@ -21,6 +21,9 @@ namespace aura {
 namespace test {
 namespace {
 
+// Mask of the mouse buttons currently down.
+unsigned g_button_down_mask = 0;
+
 class UIControlsOzone : public ui_controls::UIControlsAura {
  public:
   UIControlsOzone(WindowTreeHost* host) : host_(host) {}
@@ -42,7 +45,7 @@ class UIControlsOzone : public ui_controls::UIControlsAura {
       bool alt,
       bool command,
       const base::Closure& closure) override {
-    int flags = button_down_mask_;
+    int flags = g_button_down_mask;
 
     if (control) {
       flags |= ui::EF_CONTROL_DOWN;
@@ -111,12 +114,12 @@ class UIControlsOzone : public ui_controls::UIControlsAura {
 
     ui::EventType event_type;
 
-    if (button_down_mask_)
+    if (g_button_down_mask)
       event_type = ui::ET_MOUSE_DRAGGED;
     else
       event_type = ui::ET_MOUSE_MOVED;
 
-    PostMouseEvent(event_type, host_location, button_down_mask_, 0);
+    PostMouseEvent(event_type, host_location, g_button_down_mask, 0);
 
     RunClosureAfterAllPendingUIEvents(closure);
     return true;
@@ -157,14 +160,14 @@ class UIControlsOzone : public ui_controls::UIControlsAura {
     }
 
     if (state & ui_controls::DOWN) {
-      button_down_mask_ |= flag;
+      g_button_down_mask |= flag;
       PostMouseEvent(ui::ET_MOUSE_PRESSED, host_location,
-                     button_down_mask_ | flag, flag);
+                     g_button_down_mask | flag, flag);
     }
     if (state & ui_controls::UP) {
-      button_down_mask_ &= ~flag;
+      g_button_down_mask &= ~flag;
       PostMouseEvent(ui::ET_MOUSE_RELEASED, host_location,
-                     button_down_mask_ | flag, flag);
+                     g_button_down_mask | flag, flag);
     }
 
     RunClosureAfterAllPendingUIEvents(closure);
@@ -229,9 +232,6 @@ class UIControlsOzone : public ui_controls::UIControlsAura {
 
   WindowTreeHost* host_;
 
-  // Mask of the mouse buttons currently down.
-  unsigned button_down_mask_ = 0;
-
   DISALLOW_COPY_AND_ASSIGN(UIControlsOzone);
 };