Small optimization for <webview> tooltips.

content/browser/browser_plugin/browser_plugin_guest.cc

 // Copyright (c) 2012 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 "content/browser/browser_plugin/browser_plugin_guest.h"
 
 #include <algorithm>
 
 #include "base/message_loop/message_loop.h"
 #include "base/pickle.h"
@@ skipping 111 matching lines @@
   if (rwhv) {
     ViewHostMsg_TextInputState_Params params;
     params.type = last_text_input_type_;
     params.mode = last_input_mode_;
     params.can_compose_inline = last_can_compose_inline_;
     rwhv->TextInputStateChanged(params);
   }
 }
 
 void BrowserPluginGuest::SetTooltipText(const base::string16& tooltip_text) {
+  if (tooltip_text == current_tooltip_text_)
+    return;
+  current_tooltip_text_ = tooltip_text;
+
   SendMessageToEmbedder(new BrowserPluginMsg_SetTooltipText(
       browser_plugin_instance_id_, tooltip_text));
 }
 
 bool BrowserPluginGuest::LockMouse(bool allowed) {
   if (!attached() || (mouse_locked_ == allowed))
     return false;
 
   return embedder_web_contents()->GotResponseToLockMouseRequest(allowed);
 }
@@ skipping 667 matching lines @@
 void BrowserPluginGuest::OnImeCompositionRangeChanged(
       const gfx::Range& range,
       const std::vector<gfx::Rect>& character_bounds) {
   static_cast<RenderWidgetHostViewBase*>(
       web_contents()->GetRenderWidgetHostView())->ImeCompositionRangeChanged(
           range, character_bounds);
 }
 #endif
 
 }  // namespace content