Re-implement form validation message UI with native widgets (Views)

chrome/renderer/validation_message_agent.cc

Index: chrome/renderer/validation_message_agent.cc
diff --git a/chrome/renderer/validation_message_agent.cc b/chrome/renderer/validation_message_agent.cc
index 8be1280b7fa145a1c0b88b998431905b5d202af8..dcd96880907a06a3bb61ed2c93a9c65716f80498 100644
--- a/chrome/renderer/validation_message_agent.cc
+++ b/chrome/renderer/validation_message_agent.cc
@@ -12,9 +12,9 @@
 ValidationMessageAgent::ValidationMessageAgent(content::RenderView* render_view)
     : content::RenderViewObserver(render_view)
 {
-#if defined(OS_MACOSX)
+#if defined(OS_MACOSX) || defined(TOOLKIT_VIEWS)
   // TODO(tkent): enable this for other platforms.
-  // crbug.com/235717, crbug.com/235719, crbug.com/235721.
+  // crbug.com/235717, crbug.com/235721.
   render_view->GetWebView()->setValidationMessageClient(this);
 #endif
 }