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..5ce5f48efd203577e3d7730d614234e97a57e48b 100644
--- a/components/arc/common/app.mojom
+++ b/components/arc/common/app.mojom
@@ -160,6 +160,22 @@ interface AppHost {
                                          string intent_uri);
 };
 
+// Next method ID: 1
+// The GetRecentAndSuggestedApps interface calls an Phonesky API that starts
+// asynchronous tasks and returns results one by one.
+interface AppDiscoveryResultsReceiver {
+  // Notifies that a result app of a Playstore app query is ready.

[Luis Héctor Chávez, 2017/06/12 21:03:59]

Mention that this is expected to be called multiple times.

[Jiaquan He, 2017/06/14 22:31:02]

Done.

+  OnResult@0(string launch_intent_uri,
+             string install_intent_uri,
+             string label,
+             bool is_instant_app,
+             bool is_recent,
+             string publisher_name,
+             array<uint8> icon_png_data);
+  // Notifies that all results are returned.
+  OnComplete@1();
+};
+
 // TODO(lhchavez): Migrate all request/response messages to Mojo.
 // Next method ID: 16
 // Deprecated method ID: 9
@@ -233,4 +249,9 @@ 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 Playstore apps.
+  [MinVersion=18] GetRecentAndSuggestedApps@16(string query,

[Luis Héctor Chávez, 2017/06/12 21:03:59]

nit:

  [MinVersion=18] GetRecentAndSuggestedApps@16(
      string query, int32_t max_results,
      AppDiscoveryResultsReceiver receiver);

[Jiaquan He, 2017/06/14 22:31:02]

Changed to returning a list of results at once.

+                                               int32 max_results,
+                                               AppDiscoveryResultsReceiver receiver);
 };