Add accessibility_perftests

Recently there have been performance improvements in ui/accessibility.
This CL creates BUILD.gn entry for accessibility_perftests.exe which
will be used to run performance tests for this directory.

With this CL, I'm adding perf tests for the following methods :
AXPosition<>::AsTreePosition
AXPosition<>::AsLeafTextPosition

Bug: 928948
Change-Id: Iedbb274868a42009766de31d6f8b8731640847e8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1838264Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Brian Sheedy <bsheedy@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Adam Ettenberger <adettenb@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#708232}

BUILD.gn

@@ -147,6 +147,7 @@ group("gn_all") {
       "//third_party/webrtc/rtc_tools:frame_analyzer",
       "//tools/perf/clear_system_cache",
       "//tools/polymer:polymer_tools_python_unittests",
+      "//ui/accessibility:accessibility_perftests",
       "//ui/accessibility:accessibility_unittests",
       "//ui/accessibility/extensions",
     ]

ui/accessibility/BUILD.gn

@@ -337,3 +337,21 @@ fuzzer_test("ax_table_fuzzer") {
 
   seed_corpus = "fuzz_corpus"
 }
+
+test("accessibility_perftests") {
+  testonly = true
+  sources = [
+    "ax_node_position_perftest.cc",
+  ]
+
+  deps = [
+    "//base",
+    "//base/test:test_support",
+    "//mojo/core/test:run_all_unittests",
+    "//skia",
+    "//testing/gmock",
+    "//testing/gtest",
+    "//testing/perf",
+    "//ui/accessibility/mojom",
+  ]
+}

ui/accessibility/ax_node_position_perftest.cc

+// Copyright 2019 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 "base/strings/stringprintf.h"
+#include "base/timer/lap_timer.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/perf/perf_result_reporter.h"
+#include "ui/accessibility/ax_node_position.h"
+#include "ui/accessibility/ax_serializable_tree.h"
+#include "ui/accessibility/ax_tree_serializer.h"
+#include "ui/accessibility/ax_tree_update.h"
+
+namespace ui {
+
+using TestPositionType = std::unique_ptr<AXPosition<AXNodePosition, AXNode>>;
+
+namespace {
+
+constexpr int kLaps = 5000;
+constexpr int kWarmupLaps = 5;
+constexpr char kMetricCallsPerSecondRunsPerS[] = "calls_per_second";
+
+class AXPositionPerfTest : public testing::Test {
+ public:
+  AXPositionPerfTest() = default;
+  ~AXPositionPerfTest() override = default;
+
+ protected:
+  void SetUp() override;
+  void TearDown() override;
+
+  perf_test::PerfResultReporter SetUpReporter(const std::string& story) {
+    perf_test::PerfResultReporter reporter("AXPositionPerfTest.", story);
+    reporter.RegisterImportantMetric(kMetricCallsPerSecondRunsPerS, "runs/s");
+    return reporter;
+  }
+
+  AXTree tree_;
+
+  DISALLOW_COPY_AND_ASSIGN(AXPositionPerfTest);
+};
+
+void AXPositionPerfTest::SetUp() {
+  // Setup a root with 5 child kGenericContainer with 5 kStaticText each.
+  // Each kStaticText contains 5 characters of text.
+  //
+  // +------------------------+--------------+
+  // | Tree Hierarchy + Role  | anchor_id(s) |
+  // +------------------------+--------------+
+  // | ++kRootWebArea         | 1            |
+  // | ++++kGenericContainer  | 2            |
+  // | ++++++kStaticText      | 7 - 11       |
+  // | ++++kGenericContainer  | 3            |
+  // | ++++++kStaticText      | 12 - 16      |
+  // | ++++kGenericContainer  | 4            |
+  // | ++++++kStaticText      | 17 - 21      |
+  // | ++++kGenericContainer  | 5            |
+  // | ++++++kStaticText      | 22 - 26      |
+  // | ++++kGenericContainer  | 6            |
+  // | ++++++kStaticText      | 27 - 31      |
+  // +------------------------+--------------+
+
+  constexpr int kNumberOfGroups = 5;
+  constexpr int kStaticTextNodesPerGroup = 5;
+  constexpr int kNumberOfStaticTextNodes =
+      kNumberOfGroups * kStaticTextNodesPerGroup;
+
+  constexpr int kGroupNodesStartIndex = 1;
+  constexpr int kStaticTextNodesStartIndex =
+      kGroupNodesStartIndex + kNumberOfGroups;
+
+  AXNode::AXID current_id = 0;
+  std::vector<AXNodeData> nodes;
+  nodes.resize(1 + kNumberOfGroups + kNumberOfStaticTextNodes);
+
+  AXNodeData& root_data = nodes[0];
+  root_data.id = ++current_id;
+  root_data.role = ax::mojom::Role::kRootWebArea;
+
+  for (int group_index = 0; group_index < kNumberOfGroups; ++group_index) {
+    AXNodeData& group = nodes[kGroupNodesStartIndex + group_index];
+    group.id = ++current_id;
+    group.role = ax::mojom::Role::kGenericContainer;
+    root_data.child_ids.push_back(group.id);
+  }
+
+  for (int text_index = 0; text_index < kNumberOfStaticTextNodes;
+       ++text_index) {
+    const int group_index = text_index / kStaticTextNodesPerGroup;
+    AXNodeData& group = nodes[kGroupNodesStartIndex + group_index];
+    AXNodeData& static_text = nodes[kStaticTextNodesStartIndex + text_index];
+    static_text.id = ++current_id;
+    static_text.role = ax::mojom::Role::kStaticText;
+    static_text.SetName(base::StringPrintf("id_%02X", static_text.id));
+    group.child_ids.push_back(static_text.id);
+  }
+
+  AXTreeUpdate initial_state;
+  initial_state.root_id = nodes[0].id;
+  initial_state.nodes = nodes;
+  initial_state.has_tree_data = true;
+  initial_state.tree_data.tree_id = AXTreeID::CreateNewAXTreeID();
+  initial_state.tree_data.title = "Perftest title";
+  AXSerializableTree src_tree(initial_state);
+
+  std::unique_ptr<AXTreeSource<const AXNode*, AXNodeData, AXTreeData>>
+      tree_source(src_tree.CreateTreeSource());
+  AXTreeSerializer<const AXNode*, AXNodeData, AXTreeData> serializer(
+      tree_source.get());
+  AXTreeUpdate update;
+  serializer.SerializeChanges(src_tree.root(), &update);
+  ASSERT_TRUE(tree_.Unserialize(update));
+  AXNodePosition::SetTree(&tree_);
+}
+
+void AXPositionPerfTest::TearDown() {
+  AXNodePosition::SetTree(nullptr);
+}
+
+}  // namespace
+
+TEST_F(AXPositionPerfTest, AsTreePositionFromTextPosition) {
+  TestPositionType text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, /*anchor_id=*/1, /*text_offset=*/103,
+      ax::mojom::TextAffinity::kDownstream);
+
+  // The time limit is unused. Use kLaps for the check interval so the time is
+  // only measured once.
+  base::LapTimer timer(kWarmupLaps, base::TimeDelta(), kLaps);
+  for (int i = 0; i < kLaps + kWarmupLaps; ++i) {
+    TestPositionType as_tree_position = text_position->AsTreePosition();
+    timer.NextLap();
+  }
+
+  auto reporter = SetUpReporter("AsTreePositionFromTextPosition");
+  reporter.AddResult(kMetricCallsPerSecondRunsPerS, timer.LapsPerSecond());
+}
+
+TEST_F(AXPositionPerfTest, AsLeafTextPositionFromTextPosition) {
+  TestPositionType text_position = AXNodePosition::CreateTextPosition(
+      tree_.data().tree_id, /*anchor_id=*/1, /*text_offset=*/103,
+      ax::mojom::TextAffinity::kDownstream);
+
+  // The time limit is unused. Use kLaps for the check interval so the time is
+  // only measured once.
+  base::LapTimer timer(kWarmupLaps, base::TimeDelta(), kLaps);
+  for (int i = 0; i < kLaps + kWarmupLaps; ++i) {
+    TestPositionType as_tree_position = text_position->AsLeafTextPosition();
+    timer.NextLap();
+  }
+
+  auto reporter = SetUpReporter("AsLeafTextPositionFromTextPosition");
+  reporter.AddResult(kMetricCallsPerSecondRunsPerS, timer.LapsPerSecond());
+}
+
+TEST_F(AXPositionPerfTest, AsLeafTextPositionFromTreePosition) {
+  TestPositionType tree_position = AXNodePosition::CreateTreePosition(
+      tree_.data().tree_id, /*anchor_id=*/1, /*child_index=*/4);
+
+  base::LapTimer timer(kWarmupLaps, base::TimeDelta(), kLaps);
+  for (int i = 0; i < kLaps + kWarmupLaps; ++i) {
+    TestPositionType as_tree_position = tree_position->AsLeafTextPosition();
+    timer.NextLap();
+  }
+
+  auto reporter = SetUpReporter("AsLeafTextPositionFromTreePosition");
+  reporter.AddResult(kMetricCallsPerSecondRunsPerS, timer.LapsPerSecond());
+}
+
+}  // namespace ui