Forward MIME types to BrowserPlugin when a viewer is specified.

chrome/browser/extensions/api/streams_private/streams_private_api.cc

Index: chrome/browser/extensions/api/streams_private/streams_private_api.cc
diff --git a/chrome/browser/extensions/api/streams_private/streams_private_api.cc b/chrome/browser/extensions/api/streams_private/streams_private_api.cc
index 66bf858d750fbf075e72c41c370d6664818f77e9..05763c7e64c8f4cc8230887295087a4e9cb7974a 100644
--- a/chrome/browser/extensions/api/streams_private/streams_private_api.cc
+++ b/chrome/browser/extensions/api/streams_private/streams_private_api.cc
@@ -61,13 +61,19 @@ void StreamsPrivateAPI::ExecuteMimeTypeHandler(
     const std::string& extension_id,
     const content::WebContents* web_contents,
     scoped_ptr<content::StreamHandle> stream,
+    const std::string& view_id,
     int64 expected_content_size) {
   // Create the event's arguments value.
   streams_private::StreamInfo info;
   info.mime_type = stream->GetMimeType();
   info.original_url = stream->GetOriginalURL().spec();
   info.stream_url = stream->GetURL().spec();
-  info.tab_id = ExtensionTabUtil::GetTabId(web_contents);
+
+  if (view_id.empty()) {
+    info.tab_id.reset(new int(ExtensionTabUtil::GetTabId(web_contents)));
+  } else {
+    info.view_id.reset(new std::string(view_id));
+  }
 
   int size = -1;
   if (expected_content_size <= INT_MAX)