Include referrer chain with inline install requests.

chrome/browser/extensions/webstore_standalone_installer.h

Index: chrome/browser/extensions/webstore_standalone_installer.h
diff --git a/chrome/browser/extensions/webstore_standalone_installer.h b/chrome/browser/extensions/webstore_standalone_installer.h
index 73110be587cb4aca068768e948ad475d69339ae9..5390a0bc80a0f7b77bb110253e56fe49feba923e 100644
--- a/chrome/browser/extensions/webstore_standalone_installer.h
+++ b/chrome/browser/extensions/webstore_standalone_installer.h
@@ -91,6 +91,12 @@ class WebstoreStandaloneInstaller
   // Allows subclasses to set properties of the install data.
   virtual void InitInstallData(ActiveInstallData* install_data) const;
 
+  // Gives subclasses an opportunity to customize the webstore data request
+  // (eg, add post data) before sending. The default implementation starts
+  // the request; subclasses overriding this are responsible for calling Start
+  // on the |fetcher| themselves once they are ready for it.
+  virtual void OnBeforeWebstoreDataRequest(WebstoreDataFetcher* fetcher);
+
   // Called at certain check points of the workflow to decide whether it makes
   // sense to proceed with installation. A requestor can be a website that
   // initiated an inline installation, or a command line option.