Added NavigationContext::IsPost.

ios/web/public/web_state/navigation_context.h

 // Copyright 2017 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.
 
 #ifndef IOS_WEB_PUBLIC_WEB_STATE_NAVIGATION_CONTEXT_H_
 #define IOS_WEB_PUBLIC_WEB_STATE_NAVIGATION_CONTEXT_H_
 
 #import <Foundation/Foundation.h>
 
 #include "ui/base/page_transition_types.h"
@@ skipping 24 matching lines @@
   // Returns the page transition type for this navigation.
   virtual ui::PageTransition GetPageTransition() const = 0;
 
   // Whether the navigation happened within the same document. Examples of same
   // document navigations are:
   // * reference fragment navigations
   // * pushState/replaceState
   // * same document history navigation
   virtual bool IsSameDocument() const = 0;
 
+  // Whether the navigation is done using HTTP POST method. This may change
+  // during the navigation (e.g. after encountering a server redirect).
+  //
+  // Note: page and frame navigations can only be done using POST or GET
+  // methods Therefore API exposes only |bool IsPost()| as opposed to
+  // |const std::string& GetMethod()| method.
+  virtual bool IsPost() const = 0;
+
   // Returns error if the navigation has failed.
   virtual NSError* GetError() const = 0;
 
   // Returns the response headers for the request, or null if there aren't any
   // response headers or they have not been received yet. The response headers
   // returned should not be modified, as modifications will not be reflected.
   virtual net::HttpResponseHeaders* GetResponseHeaders() const = 0;
 
   virtual ~NavigationContext() {}
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_PUBLIC_WEB_STATE_NAVIGATION_CONTEXT_H_