Make overriding BrowserContext::RegisterPrefs actually work

We were calling it before derived classes' vtables were set up. Now we wait to
call it until the BrowserContext is fully constructed.

brightray/browser/browser_context.cc

@@ -48,6 +48,9 @@ private:
 };
 
 BrowserContext::BrowserContext() : resource_context_(new ResourceContext) {
+}
+
+void BrowserContext::Initialize() {
   auto prefs_path = GetPath().Append(FILE_PATH_LITERAL("Preferences"));
   PrefServiceBuilder builder;
   builder.WithUserFilePrefs(prefs_path,

brightray/browser/browser_context.h

@@ -22,6 +22,8 @@ public:
   BrowserContext();
   ~BrowserContext();
 
+  void Initialize();
+
   net::URLRequestContextGetter* CreateRequestContext(content::ProtocolHandlerMap*);
 
   PrefService* prefs() { return prefs_.get(); }

brightray/browser/browser_main_parts.cc

@@ -22,6 +22,7 @@ BrowserMainParts::~BrowserMainParts() {
 
 void BrowserMainParts::PreMainMessageLoopRun() {
   browser_context_.reset(CreateBrowserContext());
+  browser_context_->Initialize();
 
   // These two objects are owned by devtools_http_handler_.
   auto delegate = new DevToolsDelegate;