Include referrer chain with inline install requests.

chrome/browser/extensions/webstore_data_fetcher.h

Index: chrome/browser/extensions/webstore_data_fetcher.h
diff --git a/chrome/browser/extensions/webstore_data_fetcher.h b/chrome/browser/extensions/webstore_data_fetcher.h
index bcb48a5cbd217061b8face84d7ba8c2e0929497b..7179fb7cf7d4e4257aa1b4094fdc8c0810fa5442 100644
--- a/chrome/browser/extensions/webstore_data_fetcher.h
+++ b/chrome/browser/extensions/webstore_data_fetcher.h
@@ -37,6 +37,10 @@ class WebstoreDataFetcher : public base::SupportsWeakPtr<WebstoreDataFetcher>,
                       const std::string webstore_item_id);
   ~WebstoreDataFetcher() override;
 
+  // Makes this request use a POST instead of GET, and sends |json| in the
+  // body of the request. If |json| is empty, this is a no-op.
+  void SetJsonPostData(const std::string& json);
+
   void Start();
 
   void set_max_auto_retries(int max_retries) {
@@ -54,6 +58,7 @@ class WebstoreDataFetcher : public base::SupportsWeakPtr<WebstoreDataFetcher>,
   net::URLRequestContextGetter* request_context_;
   GURL referrer_url_;
   std::string id_;
+  std::string json_post_data_;
 
   // For fetching webstore JSON data.
   std::unique_ptr<net::URLFetcher> webstore_data_url_fetcher_;