[downloads] Set initiator when handling downloads via a[download]

content/browser/renderer_host/render_view_host_unittest.cc

Index: content/browser/renderer_host/render_view_host_unittest.cc
diff --git a/content/browser/renderer_host/render_view_host_unittest.cc b/content/browser/renderer_host/render_view_host_unittest.cc
index 725c9e5555e88521fee89aa02ade9ccaa37aeca4..57418fc2e6421a4f17050cb83ac7d1bae9d3de84 100644
--- a/content/browser/renderer_host/render_view_host_unittest.cc
+++ b/content/browser/renderer_host/render_view_host_unittest.cc
@@ -283,6 +283,7 @@ class TestSaveImageFromDataURL : public RenderFrameMessageFilter {
                    int render_frame_id,
                    const GURL& url,
                    const Referrer& referrer,
+                   const url::Origin& initiator,
                    const base::string16& suggested_name,
                    const bool use_prompt) const override {
     url_string_ = url.spec();