Do not inject windowID into non-HTML documents.

ios/web/web_state/ui/crw_web_controller.mm

 // Copyright 2012 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_web_controller.h"
 
 #import <WebKit/WebKit.h>
 
 #import <objc/runtime.h>
 #include <stddef.h>
@@ skipping 5234 matching lines @@
   // This must be reset at the end, since code above may need information about
   // the pending load.
   _pendingNavigationInfo.reset();
   _certVerificationErrors->Clear();
 }
 
 - (void)webView:(WKWebView*)webView
     didCommitNavigation:(WKNavigation*)navigation {
   DCHECK_EQ(_webView, webView);
   _certVerificationErrors->Clear();
-  // This point should closely approximate the document object change, so reset
-  // the list of injected scripts to those that are automatically injected.
-  _injectedScriptManagers.reset([[NSMutableSet alloc] init]);
-  [self injectWindowID];
 
   // This is the point where the document's URL has actually changed, and
   // pending navigation information should be applied to state information.
   [self setDocumentURL:net::GURLWithNSURL([_webView URL])];
 
   if (!_lastRegisteredRequestURL.is_valid() &&
       _documentURL != _lastRegisteredRequestURL) {
     // if |_lastRegisteredRequestURL| is an invalid URL, then |_documentURL|
     // will be "about:blank".
     [[self sessionController] updatePendingEntry:_documentURL];
   }
   DCHECK(_documentURL == _lastRegisteredRequestURL ||
          (!_lastRegisteredRequestURL.is_valid() &&
           _documentURL.spec() == url::kAboutBlankURL));
 
   self.webStateImpl->OnNavigationCommitted(_documentURL);
   [self commitPendingNavigationInfo];
   if ([self currentBackForwardListItemHolder]->navigation_type() ==
       WKNavigationTypeBackForward) {
     // A fast back/forward won't call decidePolicyForNavigationResponse, so
     // the MIME type needs to be updated explicitly.
     NSString* storedMIMEType =
         [self currentBackForwardListItemHolder]->mime_type();
     if (storedMIMEType) {
       self.webStateImpl->SetContentsMimeType(
           base::SysNSStringToUTF8(storedMIMEType));
     }
   }
+
+  // This point should closely approximate the document object change, so reset
+  // the list of injected scripts to those that are automatically injected.
+  _injectedScriptManagers.reset([[NSMutableSet alloc] init]);
+  if ([self contentIsHTML] || self.webState->GetContentsMimeType().empty()) {
+    // In unit tests MIME type will be empty, because loadHTML:forURL: does not
+    // notify web view delegate about received response, so web controller does
+    // not get a chance to properly update MIME type.
+    [self injectWindowID];
+  }
+
   [self webPageChanged];
 
   [self updateSSLStatusForCurrentNavigationItem];
 
   // Attempt to update the HTML5 history state.
   [self updateHTML5HistoryState];
 
   // Report cases where SSL cert is missing for a secure connection.
   if (_documentURL.SchemeIsCryptographic()) {
     scoped_refptr<net::X509Certificate> cert =
@@ skipping 488 matching lines @@
   }
 
   return web::WEB_VIEW_DOCUMENT_TYPE_GENERIC;
 }
 
 - (NSString*)refererFromNavigationAction:(WKNavigationAction*)action {
   return [action.request valueForHTTPHeaderField:@"Referer"];
 }
 
 @end