Added experimental Share API on Android behind flag.

chrome/android/java/src/org/chromium/chrome/browser/webshare/ShareServiceImplementationFactory.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.webshare;
+
+import org.chromium.content.browser.InterfaceRegistry.ImplementationFactory;
+import org.chromium.content_public.browser.WebContents;
+import org.chromium.mojom.webshare.ShareService;
+
+/**
+ * Factory that creates instances of ShareService.
+ */
+public class ShareServiceImplementationFactory implements ImplementationFactory<ShareService> {
+    private final WebContents mWebContents;
+
+    public ShareServiceImplementationFactory(WebContents webContents) {
+        mWebContents = webContents;
+    }
+
+    @Override
+    public ShareService createImpl() {
+        return new ShareServiceImpl(mWebContents);
+    }
+}