Inside of content, prefer SiteInstanceImpl to SiteInstance.

content/browser/download/mhtml_generation_manager.cc

Index: content/browser/download/mhtml_generation_manager.cc
diff --git a/content/browser/download/mhtml_generation_manager.cc b/content/browser/download/mhtml_generation_manager.cc
index ef9202330d2af6a34d9a474600a1905bf27d5b8c..2b7839d7e22e203f114d89774a2c5123e0cbb957 100644
--- a/content/browser/download/mhtml_generation_manager.cc
+++ b/content/browser/download/mhtml_generation_manager.cc
@@ -79,7 +79,7 @@ class MHTMLGenerationManager::Job : public RenderProcessHostObserver {
   // |frame_tree_node_to_content_id_| map, but with the keys translated from
   // frame_tree_node_id into a |site_instance|-specific routing_id.
   std::map<int, std::string> CreateFrameRoutingIdToContentId(
-      SiteInstance* site_instance);
+      SiteInstanceImpl* site_instance);
 
   // Id used to map renderer responses to jobs.
   // See also MHTMLGenerationManager::id_to_job_ map.
@@ -143,7 +143,7 @@ MHTMLGenerationManager::Job::~Job() {
 
 std::map<int, std::string>
 MHTMLGenerationManager::Job::CreateFrameRoutingIdToContentId(
-    SiteInstance* site_instance) {
+    SiteInstanceImpl* site_instance) {
   std::map<int, std::string> result;
   for (const auto& it : frame_tree_node_to_content_id_) {
     int ftn_id = it.first;
@@ -178,7 +178,7 @@ bool MHTMLGenerationManager::Job::SendToNextRenderFrame() {
   FrameTreeNode* ftn = FrameTreeNode::GloballyFindByID(frame_tree_node_id);
   if (!ftn)  // The contents went away.
     return false;
-  RenderFrameHost* rfh = ftn->current_frame_host();
+  RenderFrameHostImpl* rfh = ftn->current_frame_host();
 
   // Get notified if the target of the IPC message dies between responding.
   observed_renderer_process_host_.RemoveAll();