Removing NavigationRequest::TakeNavigationHandle.

This function is unused since the NavigationHandle and NavigationRequest
are kept together now.

Change-Id: I0ca24dc4dd37712c298084f7c2d2088df9a24e3c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1495547Reviewed-by: Camille Lamy <clamy@chromium.org>
Commit-Queue: Arthur Hemery <ahemery@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638219}

content/browser/frame_host/navigation_request.cc

@@ -815,11 +815,6 @@ void NavigationRequest::CreateNavigationHandle(bool is_for_commit) {
   navigation_handle_ = std::move(navigation_handle);
 }
 
-std::unique_ptr<NavigationHandleImpl>
-NavigationRequest::TakeNavigationHandle() {
-  return std::move(navigation_handle_);
-}
-
 void NavigationRequest::ResetForCrossDocumentRestart() {
   DCHECK(
       FrameMsg_Navigate_Type::IsSameDocument(common_params_.navigation_type));

content/browser/frame_host/navigation_request.h

@@ -209,9 +209,6 @@ class CONTENT_EXPORT NavigationRequest : public NavigationURLLoaderDelegate {
   // happens for renderer-initiated same-document navigations).
   void CreateNavigationHandle(bool is_for_commit);
 
-  // Returns ownership of the navigation handle.
-  std::unique_ptr<NavigationHandleImpl> TakeNavigationHandle();
-
   void set_on_start_checks_complete_closure_for_testing(
       const base::Closure& closure) {
     on_start_checks_complete_closure_ = closure;