Eat all keys involving Search when ChromeVox is on and add a pass through mode command.

chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc

Index: chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc
diff --git a/chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc b/chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc
index 6b1c91f6156ce8d842274a6bb6c92eaee0ed6fc6..c587decb0da9650291ca89fde902030b4ed684da 100644
--- a/chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc
+++ b/chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc
@@ -53,6 +53,9 @@ bool SpokenFeedbackEventRewriterDelegate::DispatchKeyEventToChromeVox(
 
   content::RenderViewHost* rvh = host->render_view_host();
 
+  // Always capture the Search key.
+  capture |= key_event.IsCommandDown();
+
   // Listen for any unhandled keyboard events from ChromeVox's background page
   // when capturing keys to reinject.
   if (capture)