Add viz-host HitTestQuery.

components/viz/common/hit_test/aggregated_hit_test_region.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_COMMON_HIT_TEST_AGGREGATED_HIT_TEST_REGION_H_
 #define COMPONENTS_VIZ_COMMON_HIT_TEST_AGGREGATED_HIT_TEST_REGION_H_
 
 #include <stdint.h>
 
 #include "components/viz/common/surfaces/surface_id.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/transform.h"
 
 namespace viz {
 
 // A AggregatedHitTestRegion element with child_count of kEndOfList indicates
 // the last element and end of the list.
-constexpr int kEndOfList = -1;
+constexpr int32_t kEndOfList = -1;
 
 // An array of AggregatedHitTestRegion elements is used to define the
 // aggregated hit-test data for the Display.
 //
 // It is designed to be in shared memory so that the viz service can
 // write the hit_test data, and the viz host can read without
 // process hops.
 struct AggregatedHitTestRegion {
   // The FrameSinkId corresponding to this region.  Events that match
   // are routed to this surface.
   FrameSinkId frame_sink_id;
 
   // Flags to indicate the type of region as defined for
   // mojom::HitTestRegion
   uint32_t flags;
 
   // The rectangle that defines the region in parent region's coordinate space.
   gfx::Rect rect;
 
   // The transform applied to the rect in parent region's coordinate space.
   gfx::Transform transform;
 
   // The number of children including their children below this entry.
   // If this element is not matched then child_count elements can be skipped
   // to move to the next entry.
-  int child_count;
+  int32_t child_count;
 };
 
 }  // namespace viz
 
 #endif  // COMPONENTS_VIZ_COMMON_HIT_TEST_AGGREGATED_HIT_TEST_REGION_H_