Adds an IOSWebViewTypeParam() method to SearchTermsData.

ios/chrome/browser/search_engines/ui_thread_search_terms_data.cc

Index: ios/chrome/browser/search_engines/ui_thread_search_terms_data.cc
diff --git a/ios/chrome/browser/search_engines/ui_thread_search_terms_data.cc b/ios/chrome/browser/search_engines/ui_thread_search_terms_data.cc
index e09d36f08c6ba84b5e85fb034ebfe8761c460eba..d6e92f6a68603d09ff80a1a02368433eed69f511 100644
--- a/ios/chrome/browser/search_engines/ui_thread_search_terms_data.cc
+++ b/ios/chrome/browser/search_engines/ui_thread_search_terms_data.cc
@@ -12,10 +12,12 @@
 #include "components/search/search.h"
 #include "components/version_info/version_info.h"
 #include "ios/chrome/browser/application_context.h"
+#include "ios/chrome/browser/experimental_flags.h"
 #include "ios/chrome/browser/google/google_brand.h"
 #include "ios/chrome/browser/google/google_url_tracker_factory.h"
 #include "ios/chrome/common/channel_info.h"
 #include "ios/web/public/web_thread.h"
+#include "net/base/escape.h"
 #include "url/gurl.h"
 
 #if defined(ENABLE_RLZ)
@@ -119,6 +121,16 @@ std::string UIThreadSearchTermsData::NTPIsThemedParam() const {
   return std::string();
 }
 
+std::string UIThreadSearchTermsData::IOSWebViewTypeParam() const {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  std::string param = experimental_flags::GetWKWebViewSearchParams();
+  if (param.empty()) {
+    return std::string();
+  }
+
+  return "&esrch=" + net::EscapeQueryParamValue(param, true);
+}
+
 std::string UIThreadSearchTermsData::GoogleImageSearchSource() const {
   DCHECK(thread_checker_.CalledOnValidThread());
   std::string version(version_info::GetProductName() + " " +