Make Clipboard.java a singleton pattern.

chrome/android/java/src/org/chromium/chrome/browser/tab/TabContextMenuItemDelegate.java

 // Copyright 2015 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.tab;
 
 import android.content.Context;
 import android.content.Intent;
 import android.net.MailTo;
 import android.net.Uri;
@@ skipping 22 matching lines @@
 import java.net.URI;
 import java.util.Locale;
 
 /**
  * A default {@link ContextMenuItemDelegate} that supports the context menu functionality in Tab.
  */
 public class TabContextMenuItemDelegate implements ContextMenuItemDelegate {
     public static final String PAGESPEED_PASSTHROUGH_HEADERS =
             "Chrome-Proxy: pass-through\nCache-Control: no-cache";
 
-    private final Clipboard mClipboard;
     private final Tab mTab;
     private boolean mLoadOriginalImageRequestedForPageLoad;
     private EmptyTabObserver mDataReductionProxyContextMenuTabObserver;
 
     /**
      * Builds a {@link TabContextMenuItemDelegate} instance.
      */
     public TabContextMenuItemDelegate(Tab tab) {
         mTab = tab;
-        mClipboard = new Clipboard(mTab.getApplicationContext());
         mDataReductionProxyContextMenuTabObserver = new EmptyTabObserver() {
             @Override
             public void onPageLoadStarted(Tab tab, String url) {
                 mLoadOriginalImageRequestedForPageLoad = false;
             }
         };
         mTab.addObserver(mDataReductionProxyContextMenuTabObserver);
     }
 
     @Override
@@ skipping 21 matching lines @@
         return isSpdyProxyEnabledForUrl(url);
     }
 
     @Override
     public boolean startDownload(String url, boolean isLink) {
         return !isLink || !mTab.shouldInterceptContextMenuDownload(url);
     }
 
     @Override
     public void onSaveToClipboard(String text, int clipboardType) {
-        mClipboard.setText(text);
+        Clipboard.getInstance().setText(text);
     }
 
     @Override
     public boolean supportsCall() {
         Intent intent = new Intent(Intent.ACTION_VIEW);
         intent.setData(Uri.parse("tel:"));
         return mTab.getWindowAndroid().canResolveActivity(intent);
     }
 
     @Override
@@ skipping 181 matching lines @@
         if (DataReductionProxySettings.getInstance().isDataReductionProxyEnabled()
                 && url != null && !url.toLowerCase(Locale.US).startsWith(
                         UrlConstants.HTTPS_URL_PREFIX)
                 && !isIncognito()) {
             return true;
         }
         return false;
     }
 
 }