Make sure there are no modifiers when escape is pressed.

content/browser/browser_plugin/browser_plugin_embedder.cc

Index: content/browser/browser_plugin/browser_plugin_embedder.cc
diff --git a/content/browser/browser_plugin/browser_plugin_embedder.cc b/content/browser/browser_plugin/browser_plugin_embedder.cc
index 6c94099f51f42941798a7aeb638105770fad9f46..f02d315b4bd25caa5f5d09235599d7101ff93ed0 100644
--- a/content/browser/browser_plugin/browser_plugin_embedder.cc
+++ b/content/browser/browser_plugin/browser_plugin_embedder.cc
@@ -157,8 +157,10 @@ void BrowserPluginEmbedder::OnAttach(
 
 bool BrowserPluginEmbedder::HandleKeyboardEvent(
     const NativeWebKeyboardEvent& event) {
-  if (event.windowsKeyCode != ui::VKEY_ESCAPE)
+  if ((event.windowsKeyCode != ui::VKEY_ESCAPE) ||
+      (event.modifiers & blink::WebInputEvent::InputModifiers)) {
     return false;
+  }
 
   bool event_consumed = false;
   GetBrowserPluginGuestManager()->ForEachGuest(