Chrome talks to Play to install WebAPKs.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkInstaller.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkInstaller.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkInstaller.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkInstaller.java
index 2b3a2c9fb66f47a8b1437241f5ee51515d29292a..6ed8b9e2ead1b877e30e3784cb59422fae941dfe 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkInstaller.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebApkInstaller.java
@@ -13,6 +13,7 @@ import android.os.Looper;
 
 import org.chromium.base.ApplicationState;
 import org.chromium.base.ApplicationStatus;
+import org.chromium.base.Callback;
 import org.chromium.base.ContentUriUtils;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.annotations.CalledByNative;
@@ -45,18 +46,40 @@ public class WebApkInstaller {
     /** Weak pointer to the native WebApkInstaller. */
     private long mNativePointer;
 
+    /** Talks to Google Play to install WebAPKs. */
+    private static GooglePlayWebApkInstallDelegate sGooglePlayWebApkInstallDelegate;
+
     private WebApkInstaller(long nativePtr) {
         mNativePointer = nativePtr;
     }
 
+    /** Sets the GooglePlayWebApkInstallDelegate. */
+    public static void setGooglePlayWebApkInstallDelegate(
+            GooglePlayWebApkInstallDelegate delegate) {
+        sGooglePlayWebApkInstallDelegate = delegate;
+    }
+
+    /** Gets the GooglePlayWebApkInstallDelegate. */
+    public static GooglePlayWebApkInstallDelegate getGooglePlayWebApkInstallDelegate() {
+        return sGooglePlayWebApkInstallDelegate;
+    }
+
     @CalledByNative
     private static WebApkInstaller create(long nativePtr) {
         return new WebApkInstaller(nativePtr);
     }
 
     @CalledByNative
+    private boolean hasGooglePlayWebApkInstallDelegate() {
+        return sGooglePlayWebApkInstallDelegate != null;
+    }
+
+    @CalledByNative
     private void destroy() {
-        ApplicationStatus.unregisterApplicationStateListener(mListener);
+        if (mListener != null) {
+            ApplicationStatus.unregisterApplicationStateListener(mListener);
+        }
+        mListener = null;
         mNativePointer = 0;
     }
 
@@ -86,7 +109,59 @@ public class WebApkInstaller {
     }
 
     /**
-     * Send intent to Android to show prompt and install downloaded WebAPK.
+     * Installs a WebAPK from Google Play and monitors the installation.
+     * @param packageName The package name of the WebAPK to install.
+     * @param version The version of WebAPK to install.
+     * @param title The title of the WebAPK to display during installation.
+     * @param token The token from WebAPK Server.
+     */
+    @CalledByNative
+    private void installWebApkFromPlayStoreAsyncAndMonitorInstallation(String packageName,
+            int version, String title, String token) {

[pkotwicz, 2016/12/02 22:27:04]

Shouldn't this method return a boolean? So that the UI is notified if the
install fails (because sGooglePlayWebApkInstallDelegate is null)

[Xi Han, 2016/12/05 17:27:54]

Done.

+        if (sGooglePlayWebApkInstallDelegate == null) return;
+
+        Callback<Boolean> callback = new Callback<Boolean>() {
+            @Override
+            public void onResult(Boolean success) {
+                if (mNativePointer != 0) {
+                    nativeOnInstallFinished(mNativePointer, success);
+                }
+            }
+        };
+        sGooglePlayWebApkInstallDelegate.installAsync(packageName, version, title, token, callback);
+    }
+
+    /**
+     * Updates a WebAPK.
+     * @param filePath File to update.
+     * @return True if the update was started. A "true" return value does not guarantee that the
+     *         update succeeds.
+     */
+    @CalledByNative
+    private boolean updateAsyncFromNative(String filePath) {
+        mIsInstall = false;
+        return installDownloadedWebApk(filePath);
+    }
+
+    /**
+     * Updates a WebAPK using Google Play.
+     * @param packageName The package name of the WebAPK to install.
+     * @param version The version of WebAPK to install.
+     * @param title The title of the WebAPK to display during installation.
+     * @param token The token from WebAPK Server.
+     */
+    @CalledByNative
+    private void updateAsyncFromPlayStore(String packageName, int version, String title,
+            String token) {

[pkotwicz, 2016/12/02 22:27:04]

Shouldn't this method return a boolean? So that the UI is notified if the
install fails (because sGooglePlayWebApkInstallDelegate is null)

[Xi Han, 2016/12/05 17:27:54]

Done.

+        if (sGooglePlayWebApkInstallDelegate == null) return;
+
+        // TODO(hanxi):crbug.com/634499. Adds a callback to show an infobar after the update
+        // succeeded.
+        sGooglePlayWebApkInstallDelegate.installAsync(packageName, version, title, token, null);

[pkotwicz, 2016/12/02 22:52:21]

You should return the return value of
GooglePlayWebApkInstallDelegate#installAsync() here

[Xi Han, 2016/12/05 17:27:54]

Done.

+    }
+
+    /**
+     * Sends intent to Android to show prompt and install downloaded WebAPK.
      * @param filePath File to install.
      */
     private boolean installDownloadedWebApk(String filePath) {
@@ -132,18 +207,6 @@ public class WebApkInstaller {
         }
     }
 
-    /**
-     * Updates a WebAPK.
-     * @param filePath File to update.
-     * @return True if the update was started. A "true" return value does not guarantee that the
-     *         update succeeds.
-     */
-    @CalledByNative
-    private boolean updateAsyncFromNative(String filePath) {
-        mIsInstall = false;
-        return installDownloadedWebApk(filePath);
-    }
-
     private ApplicationStatus.ApplicationStateListener createApplicationStateListener() {
         return new ApplicationStatus.ApplicationStateListener() {
             @Override