When the user navigates to the home page, make sure to set the RLZ string

chrome/browser/instant/instant_loader.cc

 // Copyright (c) 2011 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 "chrome/browser/instant/instant_loader.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 163 matching lines @@
   void UnregisterForPaintNotifications();
 
   // NotificationObserver:
   virtual void Observe(int type,
                        const NotificationSource& source,
                        const NotificationDetails& details) OVERRIDE;
 
   // TabContentsDelegate:
   virtual void NavigationStateChanged(const TabContents* source,
                                       unsigned changed_flags) OVERRIDE;
-  virtual std::string GetNavigationHeaders(const GURL& url) OVERRIDE;
+  virtual void AddNavigationHeaders(const GURL& url,
+                                    std::string* headers) OVERRIDE;
   virtual bool ShouldFocusConstrainedWindow() OVERRIDE;
   virtual void WillShowConstrainedWindow(TabContents* source) OVERRIDE;
   virtual bool ShouldSuppressDialogs() OVERRIDE;
   virtual void BeforeUnloadFired(TabContents* tab,
                                  bool proceed,
                                  bool* proceed_to_fire_unload) OVERRIDE;
   virtual void SetFocusToLocationBar(bool select_all) OVERRIDE;
   virtual bool ShouldFocusPageAfterCrash() OVERRIDE;
   virtual void LostCapture() OVERRIDE;
   // If the user drags, we won't get a mouse up (at least on Linux). Commit the
@@ skipping 210 matching lines @@
     // when a new renderer is created from the resize so that if we showed the
     // preview after the first paint we would end up with a white rect.
     RenderWidgetHostView *rwhv = source->GetRenderWidgetHostView();
     if (rwhv)
       RegisterForPaintNotifications(rwhv->GetRenderWidgetHost());
   } else if (source->is_crashed()) {
     PreviewPainted();
   }
 }
 
-std::string InstantLoader::TabContentsDelegateImpl::GetNavigationHeaders(
-    const GURL& url) {
-  std::string header;
+void InstantLoader::TabContentsDelegateImpl::AddNavigationHeaders(
+    const GURL& url,
+    std::string* headers) {
   net::HttpUtil::AppendHeaderIfMissing(kPreviewHeader, kPreviewHeaderValue,
-                                       &header);
-  return header;
+                                       headers);
 }
 
 bool InstantLoader::TabContentsDelegateImpl::ShouldFocusConstrainedWindow() {
   // Return false so that constrained windows are not initially focused. If
   // we did otherwise the preview would prematurely get committed when focus
   // goes to the constrained window.
   return false;
 }
 
 void InstantLoader::TabContentsDelegateImpl::WillShowConstrainedWindow(
@@ skipping 597 matching lines @@
   CommandLine* cl = CommandLine::ForCurrentProcess();
   if (cl->HasSwitch(switches::kInstantURL))
     instant_url = GURL(cl->GetSwitchValueASCII(switches::kInstantURL));
   preview_contents_->controller().LoadURL(instant_url, GURL(), transition_type);
   RenderViewHost* host = preview_contents_->render_view_host();
   host->Send(new ChromeViewMsg_SearchBoxChange(
       host->routing_id(), user_text, verbatim, 0, 0));
   frame_load_observer_.reset(new FrameLoadObserver(
       this, preview_contents()->tab_contents(), user_text, verbatim));
 }