Add viz-host HitTestQuery.

components/viz/host/hit_test/hit_test_query.h

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef COMPONENTS_VIZ_HOST_HIT_TEST_HIT_TEST_QUERY_H_
+#define COMPONENTS_VIZ_HOST_HIT_TEST_HIT_TEST_QUERY_H_
+
+#include <vector>
+
+#include "base/macros.h"
+#include "components/viz/common/hit_test/display_hit_test_data.h"
+#include "ui/gfx/geometry/point.h"
+
+namespace viz {
+namespace hit_test {
+
+struct Target {
+  cc::FrameSinkId id;
+  // |location_in_target| is in the coordinate system of the target FrameSinkId.
+  gfx::Point location_in_target;
+  uint32_t flags;

[sadrul, 2017/06/16 17:09:51]

Add a comment to point to where the flags are defined.

[riajiang, 2017/06/23 02:46:37]

Done.

+};
+
+// Finds the target for a given location based on DisplayHitTestData aggreated
+// by HitTestComponent.
+class HitTestQuery {
+ public:
+  HitTestQuery();
+  ~HitTestQuery();
+
+  // TODO(riajiang): Read from shmem directly once it's set up and delete this
+  // function. For now, use fake data.
+  void set_display_hit_test_data_list(
+      DisplayHitTestData display_hit_test_data_list) {
+    display_hit_test_data_list_ = display_hit_test_data_list;

[sadrul, 2017/06/16 17:09:51]

Use std::move

[riajiang, 2017/06/23 02:46:36]

Done.

+  }
+
+  // Find Target for |location_in_root|, including the FrameSinkId of the
+  // target, updated location in the coordinate system of the target and
+  // hit-test flags for the target.
+  Target FindTargetForLocation(const gfx::Point& location_in_root);
+
+ private:
+  DisplayHitTestData display_hit_test_data_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(HitTestQuery);
+};
+
+}  // namespace hit_test
+}  // namespace viz
+
+#endif  // COMPONENTS_VIZ_HOST_HIT_TEST_HIT_TEST_QUERY_H_