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..a46bcd87640ae165ce07a2c9b59f2009c5735ed2 100644
--- a/chrome/browser/extensions/webstore_data_fetcher.h
+++ b/chrome/browser/extensions/webstore_data_fetcher.h
@@ -8,6 +8,7 @@
 #include <memory>
 #include <string>
 
+#include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "net/url_request/url_fetcher_delegate.h"
@@ -37,6 +38,10 @@ 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(std::unique_ptr<std::string> json);
+
   void Start();
 
   void set_max_auto_retries(int max_retries) {
@@ -54,6 +59,7 @@ 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_;