Stop using CertStore which is not compatible with PlzNavigate.

content/browser/loader/navigation_resource_handler.h

Index: content/browser/loader/navigation_resource_handler.h
diff --git a/content/browser/loader/navigation_resource_handler.h b/content/browser/loader/navigation_resource_handler.h
index 6dd8f8b70925903931f8c33208d0c3dbc002bb1f..fca4a90de911810aa3f4fb59ce9e7e8273feec8d 100644
--- a/content/browser/loader/navigation_resource_handler.h
+++ b/content/browser/loader/navigation_resource_handler.h
@@ -10,7 +10,6 @@
 #include "content/browser/loader/stream_writer.h"
 
 namespace content {
-class CertStore;
 class NavigationURLLoaderImplCore;
 class ResourceDispatcherHostDelegate;
 
@@ -20,8 +19,7 @@ class NavigationResourceHandler : public ResourceHandler {
   NavigationResourceHandler(
       net::URLRequest* request,
       NavigationURLLoaderImplCore* core,
-      ResourceDispatcherHostDelegate* resource_dispatcher_host_delegate,
-      CertStore* cert_store);
+      ResourceDispatcherHostDelegate* resource_dispatcher_host_delegate);
   ~NavigationResourceHandler() override;
 
   // Called by the loader the cancel the request.
@@ -56,7 +54,6 @@ class NavigationResourceHandler : public ResourceHandler {
   NavigationURLLoaderImplCore* core_;
   StreamWriter writer_;
   ResourceDispatcherHostDelegate* resource_dispatcher_host_delegate_;
-  CertStore* cert_store_;
 
   DISALLOW_COPY_AND_ASSIGN(NavigationResourceHandler);
 };