[tbmv3] Convert accessibility metric to TBMv3

This metric corresponds to current accessibility metric:
https://source.chromium.org/chromium/chromium/src/+/master:third_party/catapult/tracing/tracing/metrics/accessibility_metric.html;drc=ae4cc909a3bb9b54c09107a87f2d3682d762e077.

Change-Id: I403d5125bee913d0eb8041dc012d60e5d68bafa6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2339335Reviewed-by: Deep Roy <dproy@chromium.org>
Commit-Queue: Julia Semavina <nuwanda@google.com>
Cr-Commit-Position: refs/heads/master@{#795525}

tools/perf/core/tbmv3/metrics/accessibility_metric.proto

+// Copyright 2020 Google LLC.
+// SPDX-License-Identifier: Apache-2.0
+
+syntax = "proto2";
+
+package perfetto.protos;
+
+import "protos/perfetto/metrics/metrics.proto";
+import "protos/perfetto/metrics/custom_options.proto";
+
+message AccessibilityMetric {
+  repeated double browser_accessibility_events = 1
+      [(unit) = "ms_smallerIsBetter"];
+  repeated double render_accessibility_events = 2
+      [(unit) = "ms_smallerIsBetter"];
+  repeated double render_accessibility_locations = 3
+      [(unit) = "ms_smallerIsBetter"];
+}
+
+extend TraceMetrics {
+  optional AccessibilityMetric accessibility_metric = 461;
+}

tools/perf/core/tbmv3/metrics/accessibility_metric.sql

+-- Copyright 2020 Google LLC.
+-- SPDX-License-Identifier: Apache-2.0
+
+CREATE VIEW browser_accessibility_events
+AS SELECT slice.dur / 1e6 as time
+FROM slice
+INNER JOIN thread_track ON slice.track_id = thread_track.id
+INNER JOIN thread USING(utid)
+WHERE slice.name = 'BrowserAccessibilityManager::OnAccessibilityEvents'
+AND thread.name = 'CrBrowserMain';
+
+CREATE VIEW renderer_main_thread_slices
+AS SELECT slice.dur / 1e6 as time, slice.name as slice_name
+FROM slice
+INNER JOIN thread_track ON slice.track_id = thread_track.id
+INNER JOIN thread USING(utid)
+WHERE thread.name = 'CrRendererMain';
+
+CREATE VIEW accessibility_metric_output AS
+SELECT AccessibilityMetric(
+  'browser_accessibility_events', (
+    SELECT RepeatedField(time)
+    FROM browser_accessibility_events
+  ),
+  'render_accessibility_events', (
+    SELECT RepeatedField(time)
+    FROM renderer_main_thread_slices
+    WHERE slice_name = 'RenderAccessibilityImpl::SendPendingAccessibilityEvents'
+  ),
+  'render_accessibility_locations', (
+    SELECT RepeatedField(time)
+    FROM renderer_main_thread_slices
+    WHERE slice_name = 'RenderAccessibilityImpl::SendLocationChanges'
+  )
+);