Consolidate all NavigationController::LoadURL and family functions

chrome/browser/instant/instant_loader.cc

Index: chrome/browser/instant/instant_loader.cc
diff --git a/chrome/browser/instant/instant_loader.cc b/chrome/browser/instant/instant_loader.cc
index 28dad8f8ddd82fd9bb6b52a1e07a65718b4fdc76..4af2b6e1a41ded9c3143f706726c1737b6c65ff9 100644
--- a/chrome/browser/instant/instant_loader.cc
+++ b/chrome/browser/instant/instant_loader.cc
@@ -756,9 +756,12 @@ bool InstantLoader::Update(TabContents* tab_contents,
     preview_tab_contents_delegate_->PrepareForNewLoad();
     frame_load_observer_.reset(NULL);
 
+    content::NavigationController::LoadURLParams load_url_params(url_);
+    load_url_params.transition_type = transition_type;
+    load_url_params.should_inherit_user_agent_override = false;

[gone, 2012/08/03 20:17:37]

Seems like this should automatically be set to false whenever the
override_user_agent boolean is set.  Change the direct setting to a function
that does this?

[boliu, 2012/08/03 20:46:27]

I'm against doing this kind of hidden "magic" logic in a simple value struct.
The struct is simply holding parameter values. If patterns like this emerge
throughout the code base, then we could add simple helper methods that make the
intention clear.

But I think in the case of user agent override, it should really be a tri-state
variable: override to true, override to false, inherit. I'll make this change
next.

+    load_url_params.is_overriding_user_agent = override_user_agent;
     preview_contents_->web_contents()->GetController().
-        LoadURLWithUserAgentOverride(url_, content::Referrer(), transition_type,
-            false, std::string(), override_user_agent);
+        LoadURLWithParams(load_url_params);
   }
   return true;
 }
@@ -1176,9 +1179,13 @@ void InstantLoader::LoadInstantURL(const TemplateURL* template_url,
   if (cl->HasSwitch(switches::kInstantURL))
     instant_url = GURL(cl->GetSwitchValueASCII(switches::kInstantURL));
 
+  content::NavigationController::LoadURLParams load_url_params(
+      instant_url);
+  load_url_params.transition_type = transition_type;
+  load_url_params.should_inherit_user_agent_override = false;
+  load_url_params.is_overriding_user_agent = override_user_agent;
   preview_contents_->web_contents()->GetController().
-      LoadURLWithUserAgentOverride(instant_url, content::Referrer(),
-          transition_type, false, std::string(), override_user_agent);
+      LoadURLWithParams(load_url_params);
 
   RenderViewHost* host = preview_contents_->web_contents()->GetRenderViewHost();
   preview_contents_->web_contents()->WasHidden();