[Android] Explicitly request all needed runtime permissions.

chrome/android/java/src/org/chromium/chrome/browser/externalnav/ExternalNavigationDelegateImpl.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.externalnav;
 
 import android.Manifest.permission;
 import android.app.Activity;
 import android.content.Context;
 import android.content.DialogInterface;
@@ skipping 408 matching lines @@
     public boolean shouldRequestFileAccess(String url, Tab tab) {
         // If the tab is null, then do not attempt to prompt for access.
         if (tab == null) return false;
 
         // If the url points inside of Chromium's data directory, no permissions are necessary.
         // This is required to prevent permission prompt when uses wants to access offline pages.
         if (url.startsWith(UrlConstants.FILE_URL_PREFIX + PathUtils.getDataDirectory())) {
             return false;
         }
 
-        return !tab.getWindowAndroid().hasPermission(permission.WRITE_EXTERNAL_STORAGE)
-                && tab.getWindowAndroid().canRequestPermission(permission.WRITE_EXTERNAL_STORAGE);
+        return !tab.getWindowAndroid().hasPermission(permission.READ_EXTERNAL_STORAGE)
+                && tab.getWindowAndroid().canRequestPermission(permission.READ_EXTERNAL_STORAGE);
     }
 
     @Override
     public void startFileIntent(final Intent intent, final String referrerUrl, final Tab tab,
             final boolean needsToCloseTab) {
         PermissionCallback permissionCallback = new PermissionCallback() {
             @Override
             public void onRequestPermissionsResult(String[] permissions, int[] grantResults) {
                 if (grantResults.length > 0
                         && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                     loadIntent(intent, referrerUrl, null, tab, needsToCloseTab, tab.isIncognito());
                 } else {
                     // TODO(tedchoc): Show an indication to the user that the navigation failed
                     //                instead of silently dropping it on the floor.
                     if (needsToCloseTab) {
                         // If the access was not granted, then close the tab if necessary.
                         closeTab(tab);
                     }
                 }
             }
         };
         tab.getWindowAndroid().requestPermissions(
-                new String[] {permission.WRITE_EXTERNAL_STORAGE}, permissionCallback);
+                new String[] {permission.READ_EXTERNAL_STORAGE}, permissionCallback);
     }
 
     private void loadIntent(Intent intent, String referrerUrl, String fallbackUrl, Tab tab,
             boolean needsToCloseTab, boolean launchIncogntio) {
         boolean needsToStartIntent = false;
         if (tab == null || tab.isClosing() || !tab.isInitialized()) {
             needsToStartIntent = true;
             needsToCloseTab = false;
         } else if (needsToCloseTab) {
             needsToStartIntent = true;
@@ skipping 140 matching lines @@
      * @param intent The bare intent we were going to send.
      */
     protected void dispatchAuthenticatedIntent(Intent intent) {
         Intent proxyIntent = new Intent(Intent.ACTION_MAIN);
         proxyIntent.setClass(getAvailableContext(), AuthenticatedProxyActivity.class);
         intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
         proxyIntent.putExtra(AuthenticatedProxyActivity.AUTHENTICATED_INTENT_EXTRA, intent);
         getAvailableContext().startActivity(proxyIntent);
     }
 }