PlzNavigate: Move navigation-level mixed content checks to the browser.

content/browser/frame_host/navigation_handle_impl.cc

Index: content/browser/frame_host/navigation_handle_impl.cc
diff --git a/content/browser/frame_host/navigation_handle_impl.cc b/content/browser/frame_host/navigation_handle_impl.cc
index 8ed60813cfc8592fe75bd843f6931c59c078c1ba..069d04391395b006bb8d91785b583e3a3fdadab0 100644
--- a/content/browser/frame_host/navigation_handle_impl.cc
+++ b/content/browser/frame_host/navigation_handle_impl.cc
@@ -14,6 +14,7 @@
 #include "content/browser/frame_host/ancestor_throttle.h"
 #include "content/browser/frame_host/debug_urls.h"
 #include "content/browser/frame_host/frame_tree_node.h"
+#include "content/browser/frame_host/mixed_content_navigation_throttle.h"
 #include "content/browser/frame_host/navigator.h"
 #include "content/browser/frame_host/navigator_delegate.h"
 #include "content/browser/loader/resource_dispatcher_host_impl.h"
@@ -30,7 +31,6 @@
 #include "content/public/common/url_constants.h"
 #include "net/base/net_errors.h"
 #include "net/url_request/redirect_info.h"
-#include "third_party/WebKit/public/platform/WebMixedContentContextType.h"
 #include "url/gurl.h"
 #include "url/url_constants.h"
 
@@ -788,6 +788,10 @@ void NavigationHandleImpl::RegisterNavigationThrottles() {
   // GetNavigationThrottles is not assigned to throttles_ directly because it
   // would overwrite any throttle previously added with
   // RegisterThrottleForTesting.
+  if (IsBrowserSideNavigationEnabled()) {
+    throttles_.insert(throttles_.end(),
+                      new MixedContentNavigationThrottle(this));
+  }
   ScopedVector<NavigationThrottle> throttles_to_register =
       GetDelegate()->CreateThrottlesForNavigation(this);
   std::unique_ptr<NavigationThrottle> devtools_throttle =