Add feature use counting for window.external.AddSearchProvider (Blink side).

chrome/renderer/external_extension.cc

Index: chrome/renderer/external_extension.cc
diff --git a/chrome/renderer/external_extension.cc b/chrome/renderer/external_extension.cc
index 014d388f581c7150bd237603c2fcc42dd813aff3..b0be4ca15ee1d3bb7edb8251e0ffff91b1f73650 100644
--- a/chrome/renderer/external_extension.cc
+++ b/chrome/renderer/external_extension.cc
@@ -116,6 +116,7 @@ void ExternalExtensionWrapper::AddSearchProvider(
 
   GURL osdd_url = GURL(webframe->document().url()).Resolve(osdd_string);
   if (!osdd_url.is_empty() && osdd_url.is_valid()) {
+    webframe->countFeatureUse(blink::WebFrame::ExternalAddSearchProvider);
     render_view->Send(new ChromeViewHostMsg_PageHasOSDD(
         render_view->GetRoutingID(), webframe->document().url(), osdd_url,
         search_provider::EXPLICIT_PROVIDER));
@@ -144,11 +145,11 @@ void ExternalExtensionWrapper::IsSearchProviderInstalled(
   search_provider::InstallState install = search_provider::DENIED;
   GURL inquiry_url = GURL(webframe->document().url()).Resolve(name);
   if (!inquiry_url.is_empty()) {
-      render_view->Send(new ChromeViewHostMsg_GetSearchProviderInstallState(
-          render_view->GetRoutingID(),
-          webframe->document().url(),
-          inquiry_url,
-          &install));
+    webframe->countFeatureUse(

[dcheng, 2015/10/17 01:15:21]

Why not just add a UMA in Chrome? It doesn't seem necessary to plumb this into
Blink?

[Evan Stade, 2015/10/18 03:26:10]

Jochen and other API owners wanted to follow the standard process for measuring
blink feature usage to determine whether we should deprecate. See
https://codereview.chromium.org/1403803003/

+        blink::WebFrame::ExternalIsSearchProviderInstalled);
+    render_view->Send(new ChromeViewHostMsg_GetSearchProviderInstallState(
+        render_view->GetRoutingID(), webframe->document().url(), inquiry_url,
+        &install));
   }
 
   if (install == search_provider::DENIED) {