Reland: Remove DCHECK_IMPLIES/CHECK_IMPLIES.

content/browser/frame_host/navigation_entry_impl.cc

 // Copyright 2013 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/navigation_entry_impl.h"
 
 #include <queue>
 
 #include "base/metrics/histogram.h"
 #include "base/strings/string_util.h"
@@ skipping 584 matching lines @@
 NavigationEntryImpl::TreeNode* NavigationEntryImpl::FindFrameEntry(
     FrameTreeNode* frame_tree_node) const {
   NavigationEntryImpl::TreeNode* node = nullptr;
   std::queue<NavigationEntryImpl::TreeNode*> work_queue;
   work_queue.push(root_node());
   while (!work_queue.empty()) {
     node = work_queue.front();
     work_queue.pop();
     if (node->MatchesFrame(frame_tree_node)) {
       // Only the root TreeNode should have a FTN ID of -1.
-      DCHECK_IMPLIES(node->frame_entry->frame_tree_node_id() == -1,
-                     node == root_node());
+      DCHECK(node->frame_entry->frame_tree_node_id() != -1 ||
+             node == root_node());
       return node;
     }
     // Enqueue any children and keep looking.
     for (auto& child : node->children)
       work_queue.push(child);
   }
   return nullptr;
 }
 
 }  // namespace content