PlzNavigate: store POST data in the FrameNavigationEntry

content/browser/frame_host/frame_navigation_entry.cc

 // Copyright 2015 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 "content/browser/frame_host/frame_navigation_entry.h"
 
 #include <utility>
 
+#include "base/strings/utf_string_conversions.h"
+#include "content/common/page_state_serialization.h"
+
 namespace content {
 
+namespace {
+
+bool RecursivelyFillBody(const ExplodedFrameState& state,
+                         const std::string& frame_name,
+                         ResourceRequestBody* body) {
+  if (base::UTF16ToUTF8(state.target.string()) == frame_name) {
+    if (!GeneratePostData(state.http_body, body))
+      return false;
+    return true;
+  }
+
+  for (const ExplodedFrameState& child_state : state.children) {
+    if (RecursivelyFillBody(child_state, frame_name, body))
+      return true;
+  }
+
+  return false;
+}
+
+}  // namespace
+
 FrameNavigationEntry::FrameNavigationEntry()
     : item_sequence_number_(-1), document_sequence_number_(-1), post_id_(-1) {}
 
 FrameNavigationEntry::FrameNavigationEntry(
     const std::string& frame_unique_name,
     int64_t item_sequence_number,
     int64_t document_sequence_number,
     scoped_refptr<SiteInstanceImpl> site_instance,
     const GURL& url,
     const Referrer& referrer,
@@ skipping 45 matching lines @@
   // location.replace is classified as NEW_PAGE rather than EXISTING_PAGE.
   // Same for document sequence number.  See https://crbug.com/596707.
   item_sequence_number_ = item_sequence_number;
 }
 
 void FrameNavigationEntry::set_document_sequence_number(
     int64_t document_sequence_number) {
   document_sequence_number_ = document_sequence_number;
 }
 
+scoped_refptr<ResourceRequestBody> FrameNavigationEntry::GetPostData() const {
+  scoped_refptr<ResourceRequestBody> body;
+  if (method_ != "POST")
+    return body;
+
+  // Generate the body from the PageState.
+  ExplodedPageState exploded_state;
+  if (!DecodePageState(page_state_.ToEncodedData(), &exploded_state))
+    return body;
+
+  body = new ResourceRequestBody();
+  if (!RecursivelyFillBody(exploded_state.top, frame_unique_name_, body.get()))

[Charlie Reis, 2016/05/11 00:00:23]

Why is this recursive?  The PageState on a FrameNavigationEntry is only for this
single frame if we're in UseSubframeNavigationEntries mode, which is the one
we'd be looking for anyway.

Will this ever be called in default Chrome?  Maybe we should remove the
recursive call and put a DCHECK that we're in UseSubframeNavigationEntries mode.

[clamy, 2016/05/11 08:54:41]

Ah I didn't know there was only one frame in the PageState. Changed the function
accordingly.

+    return nullptr;
+
+  return body;
+}
+
 }  // namespace content