Convert network hints to Mojo

components/network_hints/renderer/renderer_preconnect.h

Index: components/network_hints/renderer/renderer_preconnect.h
diff --git a/components/network_hints/renderer/renderer_preconnect.h b/components/network_hints/renderer/renderer_preconnect.h
index 39dac9312ba6fe4e4371ccb84a5456fd1b350430..9a37e3dab0316285d4838e8fe4f43757f373bc8e 100644
--- a/components/network_hints/renderer/renderer_preconnect.h
+++ b/components/network_hints/renderer/renderer_preconnect.h
@@ -18,6 +18,7 @@
 #define COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_PRECONNECT_H_
 
 #include "base/macros.h"
+#include "components/network_hints/common/network_hints.mojom.h"
 #include "url/gurl.h"
 
 namespace network_hints {
@@ -33,6 +34,12 @@ class RendererPreconnect {
   void Preconnect(const GURL& url, bool allow_credentials);
 
  private:
+  // Ensure that the Mojo connection to NetworkHints has been created.
+  void EnsureConnected();
+
+  // |EnsureConnected()| must be called before sending messages using
+  // |network_hints_|.
+  mojom::NetworkHintsPtr network_hints_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererPreconnect);
 };  // class RendererPreconnect