TabManagerDelegate: Better prioritize ARC processes.

components/arc/common/process.mojom

Index: components/arc/common/process.mojom
diff --git a/components/arc/common/process.mojom b/components/arc/common/process.mojom
index 6dd05d68d51922eb9f04399ab6d40eb9988e6e8a..f2d365f7e2e1e9723e63155d8e86707cf15072a8 100644
--- a/components/arc/common/process.mojom
+++ b/components/arc/common/process.mojom
@@ -2,7 +2,7 @@
 // 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;
 
@@ -87,6 +87,13 @@ struct RunningAppProcessInfo {
 
   // Package names running in the process.
   [MinVersion=4] array<string>? packages;
+
+  // Whether this app is focused in ARC++ multi-window environment.
+  [MinVersion=5] bool is_focused;
+
+  // Last time the process was active. Milliseconds since boot.
+  // The clock is monotonic (comes from Android System.uptimeMillis()).
+  [MinVersion=5] int64 last_activity_time;
 };
 
 interface ProcessInstance {