PlzNavigate: Enforce 'form-action' CSP on the browser-side.

content/browser/frame_host/form_submission_throttle.h

Index: content/browser/frame_host/form_submission_throttle.h
diff --git a/content/browser/frame_host/form_submission_throttle.h b/content/browser/frame_host/form_submission_throttle.h
new file mode 100644
index 0000000000000000000000000000000000000000..2144d2a9c0ee53110bf99d8af84c5e280a1980d2
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+++ b/content/browser/frame_host/form_submission_throttle.h
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+// Copyright 2017 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 CONTENT_BROWSER_FRAME_HOST_FORM_SUBMISSION_THROTTLE_H_
+#define CONTENT_BROWSER_FRAME_HOST_FORM_SUBMISSION_THROTTLE_H_
+
+#include <memory>
+#include <string>
+
+#include "base/macros.h"
+#include "content/public/browser/navigation_throttle.h"
+
+namespace content {
+class NavigationHandle;
+
+// A FormSubmissionThrottle is responsible for enforcing the 'form-action' CSP
+// directive, blocking requests which violate them.
+// It is enforcing it only if PlzNavigate is enabled. Blink is still enforcing
+// the 'form-action' directive on the renderer process.
+class CONTENT_EXPORT FormSubmissionThrottle : public NavigationThrottle {
+ public:
+  static std::unique_ptr<NavigationThrottle> MaybeCreateThrottleFor(
+      NavigationHandle* handle);
+
+  ~FormSubmissionThrottle() override;
+
+  NavigationThrottle::ThrottleCheckResult WillStartRequest() override;
+  NavigationThrottle::ThrottleCheckResult WillRedirectRequest() override;
+
+ private:
+  explicit FormSubmissionThrottle(NavigationHandle* handle);
+  NavigationThrottle::ThrottleCheckResult CheckContentSecurityPolicyFormAction(
+      bool is_redirect);
+
+  DISALLOW_COPY_AND_ASSIGN(FormSubmissionThrottle);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_FRAME_HOST_FORM_SUBMISSION_THROTTLE_H_