Add the Play Store app search to the launcher.

components/arc/common/app.mojom

Index: components/arc/common/app.mojom
diff --git a/components/arc/common/app.mojom b/components/arc/common/app.mojom
index 6348d52517e4851ebe484d466b77707bf5585eb3..b1e474b9e5caf99fed58542c0c743f76a200fee0 100644
--- a/components/arc/common/app.mojom
+++ b/components/arc/common/app.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: 20
+// Next MinVersion: 21
 
 module arc.mojom;
 
@@ -75,6 +75,19 @@ enum ShowPackageInfoPage {
   MANAGE_LINKS = 1,
 };
 
+// Describes a Play Store app discovery result.
+struct AppDiscoveryResult {
+  string? launch_intent_uri;
+  string? install_intent_uri;
+  string? label;
+  bool is_instant_app;
+  bool is_recent;
+  string? publisher_name;
+  string? formatted_price;
+  float review_score;
+  array<uint8> icon_png_data;
+};
+
 // Next method ID: 18
 interface AppHost {
   // Sends newly added ARC app to Chrome. This message is sent when ARC receives
@@ -161,7 +174,7 @@ interface AppHost {
 };
 
 // TODO(lhchavez): Migrate all request/response messages to Mojo.
-// Next method ID: 16
+// Next method ID: 17
 // Deprecated method ID: 9
 interface AppInstance {
   Init@0(AppHost host_ptr);
@@ -233,4 +246,9 @@ interface AppInstance {
   // Sends a request to ARC to uninstall the given package.  Error (if ever
   // happens) is ignored, and uninstall option should appear in the UI.
   [MinVersion=2] UninstallPackage@5(string package_name);
+
+  // Starts a query for Play Store apps.
+  [MinVersion=20] GetRecentAndSuggestedAppsFromPlayStore@16(
+      string query, int32 max_results) =>
+          (array<AppDiscoveryResult> results);
 };