Add viz-host HitTestQuery.

components/viz/hit_test/query/hit_test_query_unittest.cc

+// 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.
+
+#include "components/viz/hit_test/query/hit_test_query.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace viz {
+namespace hit_test {
+namespace test {
+
+class HitTestQueryTest : public testing::Test {
+ public:
+  HitTestQueryTest() {}
+  ~HitTestQueryTest() override {}
+
+  HitTestQuery hit_test_query_;
+
+ private:
+  // testing::Test:
+  void SetUp() override {}
+  void TearDown() override {}
+
+  DISALLOW_COPY_AND_ASSIGN(HitTestQueryTest);
+};
+
+// One embedder with a clipped child with a tab and transparent background.
+//
+//  +e-------------+
+//  |   +c---------|     Point   maps to
+//  | 1 |+a--+     |     -----   -------
+//  |   || 2 |  3  |       1        e
+//  |   |+b--------|       2        a
+//  |   ||         |       3        e ( transparent area in c )
+//  |   ||   4     |       4        b
+//  +--------------+
+//
+TEST_F(HitTestQueryTest, ClippedChildWithTabAndTransparentBackground) {
+  cc::FrameSinkId e_id = cc::FrameSinkId(1, 1);
+  cc::FrameSinkId c_id = cc::FrameSinkId(2, 2);
+  gfx::Rect e_bounds_in_e = gfx::Rect(0, 0, 600, 600);
+  gfx::Rect c_bounds_in_e = gfx::Rect(200, 100, 800, 800);
+  gfx::Rect a_bounds_in_c = gfx::Rect(0, 0, 200, 100);
+  gfx::Rect b_bounds_in_c = gfx::Rect(0, 100, 800, 600);
+  gfx::Transform transform_e_to_e, transform_a_to_c, transform_b_to_c;
+  gfx::Transform transform_c_to_e;
+  transform_c_to_e.Translate(200, 100);
+  std::vector<DisplayHitTestData> display_hit_test_data_list = {
+      {e_id, e_bounds_in_e, transform_e_to_e, 1 /* HIT_TEST_MINE */, 3},   // e

[rjkroege, 2017/06/12 17:17:24]

realistic transforms?

[riajiang, 2017/06/13 18:42:30]

In this case, bounds of e and c are in the coordinate system of e, and bounds of
a and b are in the coordinate system of c? This means transform_c_to_e would be
the only one that's not identity?

+      {e_id, c_bounds_in_e, transform_c_to_e, 0 /* HIT_TEST_BOUND */, 2},  // c
+      {c_id, a_bounds_in_c, transform_a_to_c, 1 /* HIT_TEST_MINE */, 0},   // a
+      {c_id, b_bounds_in_c, transform_b_to_c, 1 /* HIT_TEST_MINE */, 0}    // b
+  };
+  hit_test_query_.set_display_hit_test_data_list(display_hit_test_data_list);
+
+  // All points are in display coordinate systems.

[rjkroege, 2017/06/12 17:17:24]

need to be in their respective coordinate systes.

[riajiang, 2017/06/13 18:42:30]

I thought that when the point first comes in, they are in display coordinates,
and after we find the frame sink the point is going to, point would only then be
updated to be in their own coordinate systems? Did I misunderstand something?

+  gfx::Point point1(1, 1);
+  gfx::Point point2(202, 102);
+  gfx::Point point3(403, 103);
+  gfx::Point point4(202, 202);
+
+  Target target1 = hit_test_query_.FindTargetForLocation(point1);
+  EXPECT_EQ(e_id.ToString(), target1.id.ToString());
+  EXPECT_EQ(point1.ToString(), target1.location_in_target.ToString());
+  EXPECT_TRUE(target1.flags);
+
+  Target target2 = hit_test_query_.FindTargetForLocation(point2);
+  EXPECT_EQ(c_id.ToString(), target2.id.ToString());
+  EXPECT_EQ(gfx::Point(2, 2).ToString(), target2.location_in_target.ToString());
+  EXPECT_TRUE(target2.flags);
+
+  Target target3 = hit_test_query_.FindTargetForLocation(point3);
+  EXPECT_EQ(e_id.ToString(), target3.id.ToString());
+  EXPECT_EQ(point3.ToString(), target3.location_in_target.ToString());
+  EXPECT_TRUE(target3.flags);
+
+  Target target4 = hit_test_query_.FindTargetForLocation(point4);
+  EXPECT_EQ(c_id.ToString(), target4.id.ToString());
+  EXPECT_EQ(gfx::Point(2, 102).ToString(),
+            target4.location_in_target.ToString());
+  EXPECT_TRUE(target4.flags);
+}
+
+}  // namespace test
+}  // namespace hit_test
+}  // namespace viz