arc: Add GFX info into metrics IPC.

This adds interface to request new metrics
Example of usage: crrev.com/c/2426728
Payload implementation: ag/12668933

BUG=b:169211158
TEST=Locally in prototype

Change-Id: If89cb8ba6e136ac0e1bb7f60b3e078b8624b3639
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2424587
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Commit-Queue: Yury Khmel <khmel@google.com>
Auto-Submit: Yury Khmel <khmel@google.com>
Cr-Commit-Position: refs/heads/master@{#810356}

components/arc/mojom/metrics.mojom

@@ -1,7 +1,7 @@
 // Copyright 2016 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.
-// Next MinVersion: 5
+// Next MinVersion: 6
 
 module arc.mojom;
 
@@ -39,6 +39,17 @@ struct BootProgressEvent {
   int64 uptimeMillis;
 };
 
+// Describes a GFX metrics.
+struct GfxMetrics {
+  // Total frames rendered, it includes janky frames below.
+  uint64 framesTotal;
+  // Janky frames.
+  uint64 framesJanky;
+  // Maximum frame time in milliseconds of 95% of frames sorted from the
+  // shortest to longest.
+  uint32 frameTimePercentile95;
+};
+
 [Extensible]
 enum NativeBridgeType {
   // Native bridge is not used.
@@ -105,11 +116,15 @@ interface MetricsHost {
   [MinVersion=4] ReportCompanionLibApiUsage@2(CompanionLibApiId api_id);
 };
 
-// Next method ID: 2
+// Next method ID: 3
 interface MetricsInstance {
   // DEPRECATED: Please use Init@1 instead.
   InitDeprecated@0(pending_remote<MetricsHost> host_remote);
 
   // Establishes full-duplex communication with the host.
   [MinVersion=2] Init@1(pending_remote<MetricsHost> host_remote) => ();
+
+  // Requests GFX metrics for the specified package. In case of error, null is
+  // returned.
+  [MinVersion=5] GetGfxMetrics@2(string packageName) => (GfxMetrics? metrics);
 };