Prevent guest views from issuing a search for empty text.

extensions/browser/guest_view/web_view/web_view_find_helper.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "extensions/browser/guest_view/web_view/web_view_find_helper.h"
 
 #include <utility>
 
 #include "components/guest_view/browser/guest_view_event.h"
 #include "extensions/browser/api/guest_view/web_view/web_view_internal_api.h"
@@ skipping 114 matching lines @@
   if (full_options->findNext && current_find_session_.get()) {
     DCHECK(current_find_request_id_ != current_find_session_->request_id());
     current_find_session_->AddFindNextRequest(
         insert_result.first->second->AsWeakPtr());
   }
 
   // Update the current find session, if necessary.
   if (!full_options->findNext)
     current_find_session_ = insert_result.first->second;
 
+  // Handle the empty |search_text| case internally.
+  if (search_text.empty()) {
+    guest_web_contents->StopFinding(content::STOP_FIND_ACTION_CLEAR_SELECTION);
+    FindReply(current_find_request_id_, 0, gfx::Rect(), 0, true);
+    return;
+  }
+
   guest_web_contents->Find(current_find_request_id_,
                            search_text, *full_options);
 }
 
 void WebViewFindHelper::FindReply(int request_id,
                                   int number_of_matches,
                                   const gfx::Rect& selection_rect,
                                   int active_match_ordinal,
                                   bool final_update) {
   FindInfoMap::iterator find_iterator = find_info_map_.find(request_id);
@@ skipping 131 matching lines @@
   base::DictionaryValue results;
   find_results_.PrepareResults(&results);
   results.SetBoolean(webview::kFindCanceled, canceled);
 
   // Call the callback.
   find_function_->SetResult(results.DeepCopy());
   find_function_->SendResponse(true);
 }
 
 }  // namespace extensions