aura: Remove WindowTreeHost::QueryMouseLocation().

ash/magnifier/magnification_controller_unittest.cc

Index: ash/magnifier/magnification_controller_unittest.cc
diff --git a/ash/magnifier/magnification_controller_unittest.cc b/ash/magnifier/magnification_controller_unittest.cc
index 72edf410180b2d4d63d3bff1d4ddada2ce4c6091..54daf88eba900c9e15e8d22301b099305ec37adf 100644
--- a/ash/magnifier/magnification_controller_unittest.cc
+++ b/ash/magnifier/magnification_controller_unittest.cc
@@ -10,6 +10,7 @@
 #include "base/strings/stringprintf.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/env.h"
+#include "ui/aura/test/aura_test_utils.h"
 #include "ui/aura/test/event_generator.h"
 #include "ui/aura/window_tree_host.h"
 #include "ui/gfx/rect_conversions.h"
@@ -53,9 +54,10 @@ class MagnificationControllerTest: public test::AshTestBase {
   }
 
   std::string GetHostMouseLocation() {
-    gfx::Point point;
-    GetRootWindow()->GetHost()->QueryMouseLocation(&point);
-    return point.ToString();
+    const gfx::Point& location =
+        aura::test::QueryLatestMousePositionRequestInHost(
+            GetRootWindow()->GetHost());
+    return location.ToString();
   }
 
   ash::MagnificationController* GetMagnificationController() const {