DCHECK that jstring to C++ string conversions don't pass in null.

chrome/android/java/src/org/chromium/chrome/browser/contextmenu/ContextMenuHelper.java

 // Copyright 2013 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.contextmenu;
 
 import android.app.Activity;
 import android.view.ContextMenu;
 import android.view.ContextMenu.ContextMenuInfo;
 import android.view.HapticFeedbackConstants;
 import android.view.MenuItem;
 import android.view.MenuItem.OnMenuItemClickListener;
 import android.view.View;
 import android.view.View.OnCreateContextMenuListener;
 
 import org.chromium.base.VisibleForTesting;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.metrics.RecordHistogram;
 import org.chromium.chrome.browser.share.ShareHelper;
 import org.chromium.content.browser.ContentViewCore;
 import org.chromium.content_public.browser.WebContents;
 import org.chromium.ui.base.WindowAndroid;
 
 /**
  * A helper class that handles generating context menus for {@link ContentViewCore}s.
  */
 public class ContextMenuHelper implements OnCreateContextMenuListener, OnMenuItemClickListener {
-    private static final String DATA_REDUCTION_PROXY_PASSTHROUGH_HEADER =
-            "Chrome-Proxy: pass-through\r\n";
-
     private long mNativeContextMenuHelper;
 
     private ContextMenuPopulator mPopulator;
     private ContextMenuParams mCurrentContextMenuParams;
 
     private ContextMenuHelper(long nativeContextMenuHelper) {
         mNativeContextMenuHelper = nativeContextMenuHelper;
     }
 
     @CalledByNative
@@ skipping 44 matching lines @@
         }
         return false;
     }
 
     /**
      * Starts a download based on the current {@link ContextMenuParams}.
      * @param isLink Whether or not the download target is a link.
      */
     public void startContextMenuDownload(boolean isLink, boolean isDataReductionProxyEnabled) {
         if (mNativeContextMenuHelper != 0) {
-            nativeOnStartDownload(mNativeContextMenuHelper, isLink,
-                    isDataReductionProxyEnabled ? DATA_REDUCTION_PROXY_PASSTHROUGH_HEADER : null);
+            nativeOnStartDownload(mNativeContextMenuHelper, isLink, isDataReductionProxyEnabled);
         }
     }
 
     /**
      * Trigger an image search for the current image that triggered the context menu.
      */
     public void searchForImage() {
         if (mNativeContextMenuHelper == 0) return;
         nativeSearchForImage(mNativeContextMenuHelper);
     }
@@ skipping 38 matching lines @@
     @VisibleForTesting
     public ContextMenuPopulator getPopulator() {
         return mPopulator;
     }
 
     private boolean shouldShowMenu(ContextMenuParams params) {
         return (mPopulator != null && mPopulator.shouldShowContextMenu(params));
     }
 
     private native void nativeOnStartDownload(
-            long nativeContextMenuHelper, boolean isLink, String headers);
+            long nativeContextMenuHelper, boolean isLink, boolean isDataReductionProxyEnabled);
     private native void nativeSearchForImage(long nativeContextMenuHelper);
     private native void nativeShareImage(long nativeContextMenuHelper);
 }