Fixes document type detection on iOS 9.

ios/web/web_state/ui/crw_ui_web_view_web_controller.mm

 // Copyright 2014 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.
 
 #import "ios/web/web_state/ui/crw_ui_web_view_web_controller.h"
 
 #import "base/ios/ns_error_util.h"
 #import "base/ios/weak_nsobject.h"
 #include "base/json/json_reader.h"
 #include "base/json/string_escape.h"
@@ skipping 532 matching lines @@
 // The core.js cannot pass messages back to obj-c  if it is injected
 // to |WEB_VIEW_DOCUMENT| because it does not support iframe creation used
 // by core.js to communicate back. That functionality is only supported
 // by |WEB_VIEW_HTML_DOCUMENT|. |WEB_VIEW_DOCUMENT| is used when displaying
 // non-HTML contents (e.g. PDF documents).
 - (web::WebViewDocumentType)webViewDocumentType {
   // This happens during tests.
   if (!_uiWebView) {
     return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
   }
-  NSString* documentType =
-      [_uiWebView stringByEvaluatingJavaScriptFromString:
-          @"'' + document"];
-  if ([documentType isEqualToString:@"[object HTMLDocument]"])
-    return web::WEB_VIEW_DOCUMENT_TYPE_HTML;
-  else if ([documentType isEqualToString:@"[object Document]"])
-    return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
+
+  if (base::ios::IsRunningOnIOS9OrLater()) {

[Eugene But (OOO till 7-30), 2015/11/18 16:30:57]

Please explain in the comments why iOS9 implementation is different.

[stkhapugin, 2015/11/19 16:16:35]

Done.

+    NSString* documentType = [_uiWebView
+        stringByEvaluatingJavaScriptFromString:@"document.contentType"];
+    if ([documentType isEqualToString:@"text/html"])

[Eugene But (OOO till 7-30), 2015/11/18 16:30:57]

I think you also want to check for "application/xhtml+xml" and "application/xml"
MIME types. And please unify this code with -[CRWWKWebViewWebController
webViewDocumentType] by adding |documentTypeFromMIMEType:| method to
CRWWebController.

[stkhapugin, 2015/11/19 16:16:35]

Done.

+      return web::WEB_VIEW_DOCUMENT_TYPE_HTML;
+    else if ([documentType isEqualToString:@"application/pdf"])
+      return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
+  } else {
+    NSString* documentType =
+        [_uiWebView stringByEvaluatingJavaScriptFromString:@"'' + document"];
+    if ([documentType isEqualToString:@"[object HTMLDocument]"])
+      return web::WEB_VIEW_DOCUMENT_TYPE_HTML;
+    else if ([documentType isEqualToString:@"[object Document]"])
+      return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
+  }
+
   return web::WEB_VIEW_DOCUMENT_TYPE_UNKNOWN;
 }
 
 - (void)loadRequest:(NSMutableURLRequest*)request {
   DCHECK(web::GetWebClient());
   GURL requestURL = net::GURLWithNSURL(request.URL);
   // If the request is for WebUI, add information to let the network stack
   // access the requestGroupID.
   if (web::GetWebClient()->IsAppSpecificURL(requestURL)) {
     // Sub requests of a chrome:// page will not contain the user agent.
@@ skipping 984 matching lines @@
 }
 
 #pragma mark -
 #pragma mark Testing methods
 
 -(id<CRWRecurringTaskDelegate>)recurringTaskDelegate {
   return _recurringTaskDelegate;
 }
 
 @end