Prevent guest views from issuing a search for empty text.

content/browser/web_contents/web_contents_impl.cc

Index: content/browser/web_contents/web_contents_impl.cc
diff --git a/content/browser/web_contents/web_contents_impl.cc b/content/browser/web_contents/web_contents_impl.cc
index 27a226f75bb71d1735f87fcc92dbe6362e16c32b..5954abe64a7ef9bd7417be9b3e4e8af78c9294ef 100644
--- a/content/browser/web_contents/web_contents_impl.cc
+++ b/content/browser/web_contents/web_contents_impl.cc
@@ -2743,6 +2743,12 @@ bool WebContentsImpl::IsSubframe() const {
 void WebContentsImpl::Find(int request_id,
                            const base::string16& search_text,
                            const blink::WebFindOptions& options) {
+  // Cowardly refuse to search for no text.
+  if (search_text.empty()) {
+    NOTREACHED();
+    return;
+  }
+
   // See if a top level browser plugin handles the find request first.
   if (browser_plugin_embedder_ &&
       browser_plugin_embedder_->Find(request_id, search_text, options)) {