alternate ntp: implement searchbox api for instant overlay to adopt themes

chrome/browser/instant/instant_controller.cc

Index: chrome/browser/instant/instant_controller.cc
diff --git a/chrome/browser/instant/instant_controller.cc b/chrome/browser/instant/instant_controller.cc
index f70b38a0e4e43ee36f9010e9b2aec0833664c2d2..8e1e2f80650d594efb14c9d7b4f712a5082ad067 100644
--- a/chrome/browser/instant/instant_controller.cc
+++ b/chrome/browser/instant/instant_controller.cc
@@ -528,6 +528,16 @@ void InstantController::OnActiveTabModeChanged(bool active_tab_is_ntp) {
   }
 }
 
+void InstantController::OnThemeChanged(const ThemeBackgroundInfo& theme_info) {
+  if (loader_.get())
+    loader_->SendThemeBackgroundInfo(theme_info);
+}
+
+void InstantController::OnThemeAreaHeightChanged(int height) {
+  if (loader_.get())
+    loader_->SendThemeAreaHeight(height);
+}
+
 bool InstantController::commit_on_pointer_release() const {
   return GetPreviewContents() && loader_->IsPointerDownFromActivate();
 }
@@ -660,12 +670,14 @@ void InstantController::ResetLoader(const std::string& instant_url,
     loader_.reset(new InstantLoader(this, instant_url, active_tab));
     loader_->Init();
 
-    // Ensure the searchbox API has the correct focus state and context.
+    // Ensure the searchbox API has the correct focus state, context and theme-
+    // related info.
     if (is_omnibox_focused_)
       loader_->OnAutocompleteGotFocus();
     else
       loader_->OnAutocompleteLostFocus();
     loader_->OnActiveTabModeChanged(active_tab_is_ntp_);
+    browser_->UpdateThemeRelatedInfoForPreview();
 
     // Reset the loader timer.
     stale_loader_timer_.Stop();