Added experimental Share API on Android behind flag.

chrome/android/java/src/org/chromium/chrome/browser/mojo/ChromeInterfaceRegistrar.java

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.mojo;
 
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.chrome.browser.payments.PaymentRequestFactory;
+import org.chromium.chrome.browser.webshare.ShareServiceImplementationFactory;
 import org.chromium.content.browser.InterfaceRegistry;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.mojom.payments.PaymentRequest;
+import org.chromium.mojom.webshare.ShareService;
 
 /**
  * Registers interfaces exposed by Chrome in the given registry.
  */
 class ChromeInterfaceRegistrar {
     @CalledByNative
     private static void exposeInterfacesToFrame(
             InterfaceRegistry registry, WebContents webContents) {
         registry.addInterface(PaymentRequest.MANAGER, new PaymentRequestFactory(webContents));
+        registry.addInterface(
+                ShareService.MANAGER, new ShareServiceImplementationFactory(webContents));
     }
 }