[DevTools] Shows Manifest file in Sources tab

content/renderer/manifest/manifest_manager.cc

Index: content/renderer/manifest/manifest_manager.cc
diff --git a/content/renderer/manifest/manifest_manager.cc b/content/renderer/manifest/manifest_manager.cc
index b35d4a2e73dfe0d55dd11357c98885f2f065012a..b148601cbb3ad8818f6f68fc1b55ca6c873099ba 100644
--- a/content/renderer/manifest/manifest_manager.cc
+++ b/content/renderer/manifest/manifest_manager.cc
@@ -164,6 +164,8 @@ void ManifestManager::OnManifestFetchComplete(
     blink::WebConsoleMessage message;
     message.level = blink::WebConsoleMessage::LevelError;
     message.text = blink::WebString::fromUTF8(msg);
+    message.url =
+        render_frame()->GetWebFrame()->document().manifestURL().string();
     render_frame()->GetWebFrame()->addMessageToConsole(message);
   }