Refactor WebApkServiceConnectionManager.

chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkValidator.java

Index: chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkValidator.java
diff --git a/chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkValidator.java b/chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkValidator.java
index 2fc1e46694f8cdc92fbab00bdff47e7cd9de9809..65c1e680d3d365463770e26c34c7346a473f50c4 100644
--- a/chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkValidator.java
+++ b/chrome/android/webapk/libs/client/src/org/chromium/webapk/lib/client/WebApkValidator.java
@@ -14,12 +14,18 @@ import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.ResolveInfo;
 import android.content.pm.Signature;
+import android.os.Bundle;
+import android.os.RemoteException;
 import android.os.StrictMode;
 import android.support.annotation.Nullable;
 import android.text.TextUtils;
 import android.util.Log;
 
+import org.chromium.base.ContextUtils;
 import org.chromium.base.annotations.SuppressFBWarnings;
+import org.chromium.webapk.lib.common.IdentityService.IIdentityService;
+import org.chromium.webapk.lib.common.WebApkHelper;
+import org.chromium.webapk.lib.common.WebApkMetaDataKeys;
 
 import java.io.IOException;
 import java.io.RandomAccessFile;
@@ -39,11 +45,31 @@ import java.util.List;
 public class WebApkValidator {
     private static final String TAG = "WebApkValidator";
     private static final String KEY_FACTORY = "EC"; // aka "ECDSA"
+    private static final int SHELL_APK_VERSION_SUPPORTING_SWITCH_RUNTIME_HOST = 6;
 
     private static byte[] sExpectedSignature;
     private static byte[] sCommentSignedPublicKeyBytes;
     private static PublicKey sCommentSignedPublicKey;
 
+    /** Used to notified the consumer after checking the WebAPK's runtime host asynchronously. */
+    public interface CheckRuntimeHostCallback { void onCheckedRuntimeHost(String runtimeHost); }
+
+    /** Callback to call after binding to the WebAPK's Identity Service is completed or failed. */
+    private abstract static class IdentityServiceConnectionCallback
+            implements WebApkIdentityServiceConnectionManager.ConnectionCallback {
+        public abstract void onGetRuntimeHostBrowserPackageName(IIdentityService service)
+                throws RemoteException;
+
+        @Override
+        public void onConnected(IIdentityService service) {
+            try {
+                onGetRuntimeHostBrowserPackageName(service);
+            } catch (RemoteException e) {
+                Log.w(TAG, "Failed to use WebApk Identity Service.", e);
+            }
+        }
+    }
+
     /**
      * Queries the PackageManager to determine whether a WebAPK can handle the URL. Ignores whether
      * the user has selected a default handler for the URL and whether the default handler is the
@@ -103,6 +129,58 @@ public class WebApkValidator {
         return false;
     }
 
+    /**
+     * Returns the runtime host of a WebAPK, null if the WebAPK either doesn't have an Identity
+     * Service or hasn't bind to any browser yet.
+     * @param webApkPackageName The package name of the WebAPK.
+     * @param callback The callback to be called after querying the runtime host is done.
+     */
+    public static void queryWebApkRuntimeHostAsync(
+            final String webApkPackageName, final CheckRuntimeHostCallback callback) {
+        IdentityServiceConnectionCallback identityServiceCallback =
+                new IdentityServiceConnectionCallback() {
+                    @Override
+                    public void onGetRuntimeHostBrowserPackageName(IIdentityService identityService)
+                            throws RemoteException {
+                        if (identityService == null) {
+                            callback.onCheckedRuntimeHost(null);
+                            return;
+                        }
+
+                        String runtimeHost = null;
+                        try {
+                            runtimeHost = identityService.getRuntimeHostBrowserPackageName();
+                        } catch (RemoteException e) {
+                            Log.w(TAG, "Failed to get runtime host from the Identity Service.");
+                            callback.onCheckedRuntimeHost(null);
+                            return;
+                        }
+
+                        if (!TextUtils.isEmpty(runtimeHost)) {
+                            callback.onCheckedRuntimeHost(runtimeHost);
+                            return;
+                        }
+
+                        Context context = ContextUtils.getApplicationContext();

[Yaron, 2017/07/10 18:09:07]

is this the right place put this? I would think that you fail to connect from
WebApkIdentityServiceConnectionManager.connect and its currently unhandled. How
do we get here if there's no identity service?

[Xi Han, 2017/07/12 13:49:14]

Thanks for catching this! If there is no identity service, it should be handled
in line 145.

+                        Bundle metadata = WebApkHelper.readMetaData(
+                                context.getPackageManager(), webApkPackageName);
+                        if (metadata.getInt(WebApkMetaDataKeys.SHELL_APK_VERSION)
+                                < SHELL_APK_VERSION_SUPPORTING_SWITCH_RUNTIME_HOST) {
+                            String runtimeHostFromMetadata =
+                                    metadata.getString(WebApkMetaDataKeys.RUNTIME_HOST);
+                            if ((TextUtils.equals(
+                                        context.getPackageName(), runtimeHostFromMetadata))) {
+                                runtimeHost = runtimeHostFromMetadata;
+                            }
+                        }
+                        callback.onCheckedRuntimeHost(runtimeHost);
+                    }
+                };
+
+        WebApkIdentityServiceConnectionManager.getInstance().connect(

[Yaron, 2017/07/10 18:09:07]

this is never disconnected

[Xi Han, 2017/07/12 13:49:14]

I assume the disconnect is called after chrome stops. However, I didn't find a
good place to call the disconnect(). Even with explicitly called, I did see the
IdentityService#unbind() was called when Chrome is closed. Is there any concern
of not calling the disconnect()?

+                ContextUtils.getApplicationContext(), webApkPackageName, identityServiceCallback);
+    }
+
     /**
      * Fetches the list of resolve infos from the PackageManager that can handle the URL.
      *