Add system api to reach WebViewUpdateService Binder interface.

Instead of using reflection in XTS tests we add some system-apis to
enable fetching information about webview packages.

Bug: 26381867
Change-Id: If983a01b6855e4a4c08ef0b5873304918d499b76

api/system-current.txt

@@ -48858,6 +48858,24 @@ package android.webkit {
     method public abstract boolean shouldDelayChildPressedState();
   }
 
+  public final class WebViewProviderInfo implements android.os.Parcelable {
+    ctor public WebViewProviderInfo(java.lang.String, java.lang.String, boolean, boolean, java.lang.String[]);
+    method public int describeContents();
+    method public void writeToParcel(android.os.Parcel, int);
+    field public static final android.os.Parcelable.Creator<android.webkit.WebViewProviderInfo> CREATOR;
+    field public final boolean availableByDefault;
+    field public final java.lang.String description;
+    field public final boolean isFallback;
+    field public final java.lang.String packageName;
+    field public final java.lang.String[] signatures;
+  }
+
+  public final class WebViewUpdateService {
+    method public static android.webkit.WebViewProviderInfo[] getAllWebViewPackages();
+    method public static java.lang.String getCurrentWebViewPackageName();
+    method public static android.webkit.WebViewProviderInfo[] getValidWebViewPackages();
+  }
+
 }
 
 package android.widget {

core/java/android/webkit/WebViewFactory.java

@@ -573,8 +573,12 @@ public final class WebViewFactory {
                 intent.getDataString().substring("package:".length()));
     }
 
-    private static IWebViewUpdateService getUpdateService() {
-        return IWebViewUpdateService.Stub.asInterface(ServiceManager.getService("webviewupdate"));
+    private static String WEBVIEW_UPDATE_SERVICE_NAME = "webviewupdate";
+
+    /** @hide */
+    public static IWebViewUpdateService getUpdateService() {
+        return IWebViewUpdateService.Stub.asInterface(
+                ServiceManager.getService(WEBVIEW_UPDATE_SERVICE_NAME));
     }
 
     private static native boolean nativeReserveAddressSpace(long addressSpaceToReserve);

core/java/android/webkit/WebViewProviderInfo.java

@@ -16,12 +16,16 @@
 
 package android.webkit;
 
+import android.annotation.SystemApi;
 import android.os.Parcel;
 import android.os.Parcelable;
 
 import java.util.Arrays;
 
-/** @hide */
+/**
+ * @hide
+ */
+@SystemApi
 public final class WebViewProviderInfo implements Parcelable {
 
     public WebViewProviderInfo(String packageName, String description,

core/java/android/webkit/WebViewUpdateService.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.webkit;
+
+import android.annotation.SystemApi;
+import android.os.RemoteException;
+
+/**
+ * @hide
+ */
+@SystemApi
+public final class WebViewUpdateService {
+
+    private WebViewUpdateService () {}
+
+    /**
+     * Fetch all packages that could potentially implement WebView.
+     */
+    public static WebViewProviderInfo[] getAllWebViewPackages() {
+        try {
+            return getUpdateService().getAllWebViewPackages();
+        } catch (RemoteException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /**
+     * Fetch all packages that could potentially implement WebView and are currently valid.
+     */
+    public static WebViewProviderInfo[] getValidWebViewPackages() {
+        try {
+            return getUpdateService().getValidWebViewPackages();
+        } catch (RemoteException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    /**
+     * Used by DevelopmentSetting to get the name of the WebView provider currently in use.
+     */
+    public static String getCurrentWebViewPackageName() {
+        try {
+            return getUpdateService().getCurrentWebViewPackageName();
+        } catch (RemoteException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private static IWebViewUpdateService getUpdateService() {
+        return WebViewFactory.getUpdateService();
+    }
+}