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

chrome/common/instant_types.cc

Index: chrome/common/instant_types.cc
diff --git a/chrome/common/instant_types.cc b/chrome/common/instant_types.cc
index 86b44612fabcc9a54108c16704a5d697cc124e5c..ffe86f202ae5d6df8bf3317dd202274584972f42 100644
--- a/chrome/common/instant_types.cc
+++ b/chrome/common/instant_types.cc
@@ -25,3 +25,9 @@ InstantAutocompleteResult::InstantAutocompleteResult() : relevance(0) {
 
 InstantAutocompleteResult::~InstantAutocompleteResult() {
 }
+
+ThemeBackgroundInfo::ThemeBackgroundInfo() {
+}
+
+ThemeBackgroundInfo::~ThemeBackgroundInfo() {
+}