Do not navigate on loading iframes in StaticHTMLViewController.

ios/chrome/browser/ui/static_content/static_html_view_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.
 
 #include "ios/chrome/browser/ui/static_content/static_html_view_controller.h"
 
 #include <WebKit/WebKit.h>
 
 #include <stdlib.h>
 
@@ skipping 66 matching lines @@
   id<CRWNativeContentDelegate> delegate_;  // weak
 
   // The loader to navigate from the page.
   id<UrlLoader> loader_;  // weak
 }
 
 // Returns the URL of the static page to display.
 - (NSURL*)resourceURL;
 // Ensures that webView_ has been created, creating it if necessary.
 - (void)ensureWebViewCreated;
-// Determines if the page load should begin based on the current |resourceURL|.
-- (BOOL)shouldStartLoadWithRequest:(NSURLRequest*)request;
+// Determines if the page load should begin based on the current |resourceURL|
+// and the navigation type |navigationType|.
+- (BOOL)shouldStartLoadWithRequest:(NSURLRequest*)request
+                              type:(WKNavigationType)navigationType;
 @end
 
 @implementation StaticHtmlViewController
 
 - (instancetype)initWithResource:(NSString*)resource
                     browserState:(web::BrowserState*)browserState {
   DCHECK(resource);
   DCHECK(browserState);
   if ((self = [super init])) {
     resource_.reset([resource copy]);
@@ skipping 90 matching lines @@
 }
 
 - (void)setScrollEnabled:(BOOL)enabled {
   [[self scrollView] setScrollEnabled:enabled];
 }
 
 #pragma mark -
 #pragma mark WKNavigationDelegate implementation
 
 - (void)webView:(WKWebView*)webView
     decidePolicyForNavigationAction:(WKNavigationAction*)navigationAction

[Eugene But (OOO till 7-30), 2016/12/22 17:37:51]

Per offline conversation, you probably want to use
WKNavigationAction.targetFrame.mainFrame

                     decisionHandler:
                         (void (^)(WKNavigationActionPolicy))decisionHandler {
-  decisionHandler([self shouldStartLoadWithRequest:navigationAction.request]
-                      ? WKNavigationActionPolicyAllow
-                      : WKNavigationActionPolicyCancel);
+  decisionHandler(
+      [self shouldStartLoadWithRequest:navigationAction.request
+                                  type:navigationAction.navigationType]
+          ? WKNavigationActionPolicyAllow
+          : WKNavigationActionPolicyCancel);
 }
 
 #pragma mark -
 #pragma mark KVO callback
 
 - (void)observeValueForKeyPath:(NSString*)keyPath
                       ofObject:(id)object
                         change:(NSDictionary*)change
                        context:(void*)context {
   DCHECK([keyPath isEqualToString:@"title"]);
   if ([delegate_ respondsToSelector:@selector(nativeContent:titleDidChange:)]) {
     // WKWebView's |title| changes to nil when its web process crashes.
     if ([webView_ title])
       [delegate_ nativeContent:self titleDidChange:[webView_ title]];
   }
 }
 
 #pragma mark -
 #pragma mark Private
 
-- (BOOL)shouldStartLoadWithRequest:(NSURLRequest*)request {
+- (BOOL)shouldStartLoadWithRequest:(NSURLRequest*)request
+                              type:(WKNavigationType)navigationType {
   // Only allow displaying the URL which correspond to the authorized resource.
   if ([[request URL] isEqual:[self resourceURL]])
     return YES;
 
-  // All other URLs will be loaded by our UrlLoader if we have one.
-  if (loader_) {
+  // All other navigation URLs will be loaded by our UrlLoader if one exists.
+  // If type is |WKNavigationTypeOther|, the URL corresponds to an iframe.
+  if (loader_ && navigationType != WKNavigationTypeOther) {
     dispatch_async(dispatch_get_main_queue(), ^{
       [loader_ loadURL:net::GURLWithNSURL([request URL])
                    referrer:referrer_
                  transition:ui::PAGE_TRANSITION_LINK
           rendererInitiated:YES];
     });
   }
   return NO;
 }
 
@@ skipping 45 matching lines @@
         allowingReadAccessToURL:resourcesRootDirectory_];
   } else {
     NSURL* resourceURL = [self resourceURL];
     [generator_ generateHtml:^(NSString* HTML) {
       [webView loadHTMLString:HTML baseURL:resourceURL];
     }];
   }
 }
 
 @end