Moved theme related state from BrowserInstantController to InstantService.

chrome/renderer/searchbox/searchbox.cc

Index: chrome/renderer/searchbox/searchbox.cc
diff --git a/chrome/renderer/searchbox/searchbox.cc b/chrome/renderer/searchbox/searchbox.cc
index 1d873975e601c4e1e8fe4a90e35ef3ee56358c63..c7710ab1db5012ce696156297082d009342dce17 100644
--- a/chrome/renderer/searchbox/searchbox.cc
+++ b/chrome/renderer/searchbox/searchbox.cc
@@ -448,6 +448,10 @@ void SearchBox::OnSetDisplayInstantResults(bool display_instant_results) {
 }
 
 void SearchBox::OnThemeChanged(const ThemeBackgroundInfo& theme_info) {
+  // Do not send duplicate notifications.
+  if (theme_info_ == theme_info)
+    return;
+
   theme_info_ = theme_info;
   if (render_view()->GetWebView() && render_view()->GetWebView()->mainFrame()) {
     extensions_v8::SearchBoxExtension::DispatchThemeChange(