Handle floating point coordinates from ozone to exosphere

ui/aura/window.cc

Index: ui/aura/window.cc
diff --git a/ui/aura/window.cc b/ui/aura/window.cc
index 83a532b0524371c09cd0bb47625a93eedcd6e9f9..073504ab8272d1da0077fcb9f0f92c89ac97e33f 100644
--- a/ui/aura/window.cc
+++ b/ui/aura/window.cc
@@ -432,22 +432,34 @@ const Window* Window::GetChildById(int id) const {
 void Window::ConvertPointToTarget(const Window* source,
                                   const Window* target,
                                   gfx::Point* point) {
+  gfx::PointF point_f(*point);
+  ConvertPointToTargetF(source, target, &point_f);
+  *point = gfx::ToFlooredPoint(point_f);
+}
+
+// static
+void Window::ConvertPointToTargetF(const Window* source,
+                                   const Window* target,
+                                   gfx::PointF* point) {
   if (!source)
     return;
   if (source->GetRootWindow() != target->GetRootWindow()) {
+    gfx::Point floored = gfx::ToFlooredPoint(*point);

[tdresser, 2017/01/20 16:07:48]

Do we need to floor in this case?

[denniskempin, 2017/01/20 18:26:33]

I am flooring here to be able to pass a Point into the ScreenPositionClient
methods. I was trying to avoid updating the ScreenPositionClient interface to
have PointF support as well, since it has a whole bunch of implementations. 
But I can try it to see how far reaching that change would be. 

     client::ScreenPositionClient* source_client =
         client::GetScreenPositionClient(source->GetRootWindow());
     // |source_client| can be NULL in tests.
     if (source_client)
-      source_client->ConvertPointToScreen(source, point);
+      source_client->ConvertPointToScreen(source, &floored);
 
     client::ScreenPositionClient* target_client =
         client::GetScreenPositionClient(target->GetRootWindow());
     // |target_client| can be NULL in tests.
     if (target_client)
-      target_client->ConvertPointFromScreen(target, point);
+      target_client->ConvertPointFromScreen(target, &floored);
+
+    *point = gfx::PointF(floored);
   } else {
-    ui::Layer::ConvertPointToLayer(source->layer(), target->layer(), point);
+    ui::Layer::ConvertPointToLayerF(source->layer(), target->layer(), point);
   }
 }