Update cursor on Widget

Views client is supposed to use Widget::SetCursor so that
it can tell the correct cursor when asked via GetCursor on Widget.

Exo pointer should follow the same pattern and Arc notification
should simply use the cursor on the widget.

TBR=yoshiki@chromium.org
BUG=798056
TEST=manual. Cursor does not flicker on ARC notifications

Change-Id: I09e93526181c9707786ff1a9b0eb4cb682e6026b
Reviewed-on: https://chromium-review.googlesource.com/903223Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: David Reveman <reveman@chromium.org>
Commit-Queue: Mitsuru Oshima <oshima@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534601}

components/exo/pointer.cc

@@ -23,6 +23,7 @@
 #include "ui/events/event.h"
 #include "ui/gfx/geometry/vector2d_conversions.h"
 #include "ui/gfx/transform_util.h"
+#include "ui/views/widget/widget.h"
 
 #if defined(USE_OZONE)
 #include "ui/ozone/public/cursor_factory_ozone.h"
@@ -478,7 +479,22 @@ void Pointer::UpdateCursor() {
 #endif
   }
 
-  cursor_client->SetCursor(cursor_);
+  // If there is a focused surface, update its widget as the views framework
+  // expect that Widget knows the current cursor. Otherwise update the
+  // cursor directly on CursorClient.
+  if (focus_surface_) {
+    aura::Window* window = focus_surface_->window();
+    do {
+      views::Widget* widget = views::Widget::GetWidgetForNativeView(window);
+      if (widget) {
+        widget->SetCursor(cursor_);
+        return;
+      }
+      window = window->parent();
+    } while (window);
+  } else {
+    cursor_client->SetCursor(cursor_);
+  }
 }
 
 }  // namespace exo

components/exo/surface_tree_host.cc

@@ -152,10 +152,6 @@ void SurfaceTreeHost::GetHitTestMask(gfx::Path* mask) const {
     root_surface_->GetHitTestMask(mask);
 }
 
-gfx::NativeCursor SurfaceTreeHost::GetCursor(const gfx::Point& point) const {
-  return root_surface_ ? root_surface_->GetCursor() : ui::CursorType::kNull;
-}
-
 void SurfaceTreeHost::DidReceiveCompositorFrameAck() {
   active_frame_callbacks_.splice(active_frame_callbacks_.end(),
                                  frame_callbacks_);

components/exo/surface_tree_host.h

@@ -49,10 +49,6 @@ class SurfaceTreeHost : public SurfaceDelegate,
   // surface tree.
   void GetHitTestMask(gfx::Path* mask) const;
 
-  // Returns the cursor for the given position. If no cursor provider is
-  // registered then CursorType::kNull is returned.
-  gfx::NativeCursor GetCursor(const gfx::Point& point) const;
-
   // Call this to indicate that the previous CompositorFrame is processed and
   // the surface is being scheduled for a draw.
   void DidReceiveCompositorFrameAck();

ui/arc/notification/arc_notification_surface_impl.cc

@@ -30,7 +30,13 @@ class CustomWindowDelegate : public aura::WindowDelegate {
   void OnBoundsChanged(const gfx::Rect& old_bounds,
                        const gfx::Rect& new_bounds) override {}
   gfx::NativeCursor GetCursor(const gfx::Point& point) override {
-    return notification_surface_->GetCursor(point);
+    views::Widget* widget = views::Widget::GetTopLevelWidgetForNativeView(
+        notification_surface_->host_window());
+    // Exo explicitly update the cursor on widget, so just use the one
+    // set on the cursor.
+    if (widget)
+      return widget->GetNativeWindow()->GetCursor(point /* not used */);
+    return ui::CursorType::kNull;
   }
   int GetNonClientComponent(const gfx::Point& point) const override {
     return HTNOWHERE;