WebViewShell crashes on Android <= L. Fix that.

android_webview/tools/WebViewShell/src/org/chromium/webview_shell/WebViewBrowserActivity.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.webview_shell;
 
 import android.Manifest;
 import android.app.Activity;
 import android.app.AlertDialog;
 import android.content.Context;
@@ skipping 220 matching lines @@
     private void requestPermissionsForPage(PermissionRequest request) {
         // Deny any unrecognized permissions.
         for (String webkitPermission : request.getResources()) {
             if (!sPermissions.containsKey(webkitPermission)) {
                 Log.w(TAG, "Unrecognized WebKit permission: " + webkitPermission);
                 request.deny();
                 return;
             }
         }
 
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
+            request.grant(request.getResources());
+            return;
+        }
+
         // Find what Android permissions we need before we can grant these WebKit permissions.
         ArrayList<String> androidPermissionsNeeded = new ArrayList<String>();
         for (String webkitPermission : request.getResources()) {
             if (!canGrant(webkitPermission)) {
                 // We already checked for unrecognized permissions, and canGrant will skip over
                 // NO_ANDROID_PERMISSION cases, so this is guaranteed to be a regular Android
                 // permission.
                 String androidPermission = sPermissions.get(webkitPermission);
                 androidPermissionsNeeded.add(androidPermission);
             }
@@ skipping 108 matching lines @@
 
     // Returns true is a method has no arguments and returns either a boolean or a String.
     private boolean methodIsSimpleInspector(Method method) {
         Class<?> returnType = method.getReturnType();
         return ((returnType.equals(boolean.class) || returnType.equals(String.class))
                 && method.getParameterTypes().length == 0);
     }
 
     private void loadUrl(String url) {
         // Request read access if necessary
-        if ("file".equals(Uri.parse(url).getScheme())) {
-            if (PackageManager.PERMISSION_DENIED
-                    == checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE)) {
-                requestPermissionsForPage(new FilePermissionRequest(url));
-            }
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
+                && "file".equals(Uri.parse(url).getScheme())
+                && PackageManager.PERMISSION_DENIED
+                        == checkSelfPermission(Manifest.permission.READ_EXTERNAL_STORAGE)) {
+            requestPermissionsForPage(new FilePermissionRequest(url));
         }
 
         // If it is file:// and we don't have permission, they'll get the "Webpage not available"
         // "net::ERR_ACCESS_DENIED" page. When we get permission, FilePermissionRequest.grant()
         // will reload.
         mWebView.loadUrl(url);
         mWebView.requestFocus();
     }
 
     private void setUrlBarText(String url) {
@@ skipping 12 matching lines @@
     private static boolean hideKeyboard(View view) {
         InputMethodManager imm = (InputMethodManager) view.getContext().getSystemService(
                 Context.INPUT_METHOD_SERVICE);
         return imm.hideSoftInputFromWindow(view.getWindowToken(), 0);
     }
 
     private static String getUrlFromIntent(Intent intent) {
         return intent != null ? intent.getDataString() : null;
     }
 }