Remove unnecessary method from Browser object.

mandoline/ui/browser/browser.cc

Index: mandoline/ui/browser/browser.cc
diff --git a/mandoline/ui/browser/browser.cc b/mandoline/ui/browser/browser.cc
index 688d326faf8834ee337f2374a02f8571139ccf0c..202c76cae580b4859ec24bddaa3b2811b093a79b 100644
--- a/mandoline/ui/browser/browser.cc
+++ b/mandoline/ui/browser/browser.cc
@@ -21,18 +21,13 @@ Browser::Browser()
       content_(nullptr),
       omnibox_(nullptr),
       navigator_host_(this),
-      ui_(nullptr),
-      weak_factory_(this) {
+      ui_(nullptr) {
   exposed_services_impl_.AddService(this);
 }
 
 Browser::~Browser() {
 }
 
-base::WeakPtr<Browser> Browser::GetWeakPtr() {
-  return weak_factory_.GetWeakPtr();
-}
-
 void Browser::ReplaceContentWithURL(const mojo::String& url) {
   Embed(url, nullptr, nullptr);
 }