[New Tab Page] Change the mechanism to intercept online NTP errors

chrome/browser/ui/search/new_tab_page_interceptor.h

Index: chrome/browser/ui/search/new_tab_page_interceptor.h
diff --git a/chrome/browser/ui/search/new_tab_page_interceptor.h b/chrome/browser/ui/search/new_tab_page_interceptor.h
new file mode 100644
index 0000000000000000000000000000000000000000..4afdc2f09ce1e43f598eb07bb765dcbb697f6684
--- /dev/null
+++ b/chrome/browser/ui/search/new_tab_page_interceptor.h
@@ -0,0 +1,39 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_UI_SEARCH_NEW_TAB_PAGE_INTERCEPTOR_H_
+#define CHROME_BROWSER_UI_SEARCH_NEW_TAB_PAGE_INTERCEPTOR_H_
+
+#include "base/memory/weak_ptr.h"
+#include "net/url_request/url_request_interceptor.h"
+#include "url/gurl.h"
+
+class NewTabPageInterceptor : public net::URLRequestInterceptor {
+ public:
+  // Constructs the interceptor.
+  explicit NewTabPageInterceptor(const GURL& new_tab_url);
+
+  // Destroys the interceptor.

[mmenke, 2015/01/15 22:35:30]

nit:  Don't think these two comments add anything.

[Mathieu, 2015/01/22 19:21:58]

Done.

+  ~NewTabPageInterceptor() override;
+
+  base::WeakPtr<NewTabPageInterceptor> GetWeakPtr();

[mmenke, 2015/01/15 22:35:30]

Making globally accessible weak pointers is strongly recommended against. 
Admittedly, the scope of the URLRequestInterceptor is pretty limited, but I'd
still like to hide this method.

Maybe move this class into the service file's CC file, making this a private
class?

Could make it private and make the service a friend, but not a huge fan of that,
if we can avoid it.

[Mathieu, 2015/01/22 19:21:58]

Let me know if that is what you had in mind.

+
+  void SetNewTabPageURL(const GURL& new_tab_page_url);
+
+ private:
+  // Overrides from net::URLRequestInterceptor:
+  net::URLRequestJob* MaybeInterceptRequest(
+      net::URLRequest* request,
+      net::NetworkDelegate* network_delegate) const override;
+  net::URLRequestJob* MaybeInterceptResponse(
+      net::URLRequest* request,
+      net::NetworkDelegate* network_delegate) const override;
+
+  GURL new_tab_url_;
+  base::WeakPtrFactory<NewTabPageInterceptor> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(NewTabPageInterceptor);

[mmenke, 2015/01/15 22:35:30]

Should include base/macros.h for DISALLOW_COPY_AND_ASSIGN

[Mathieu, 2015/01/22 19:21:58]

Done.

+};
+
+#endif  // CHROME_BROWSER_UI_SEARCH_NEW_TAB_PAGE_INTERCEPTOR_H_