Add headers for navigation API and observer for WebLayer.

Change-Id: I965bbb46ff7dcdacad89fc1584cf1fa20f7056b7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1768867
Commit-Queue: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Darin Fisher <darin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#690091}

weblayer/BUILD.gn

@@ -50,6 +50,8 @@ jumbo_static_library("weblayer_lib") {
     "browser/web_profile_impl.h",
     "common/web_content_client.cc",
     "common/web_content_client.h",
+    "public/navigation.h",
+    "public/navigation_observer.h",
     "public/web_browser_controller.h",
     "public/web_main.h",
     "public/web_navigation_controller.h",

weblayer/public/navigation.h

+// Copyright 2019 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 WEBLAYER_PUBLIC_NAVIGATION_H_
+#define WEBLAYER_PUBLIC_NAVIGATION_H_
+
+class GURL;
+
+namespace weblayer {
+
+class Navigation {
+ public:
+  virtual ~Navigation() {}
+
+  // The URL the frame is navigating to. This may change during the navigation
+  // when encountering a server redirect.
+  virtual GURL GetURL() = 0;
+
+  // Returns the redirects that occurred on the way to the current page. The
+  // current page is the last one in the list (so even when there's no redirect,
+  // there will be one entry in the list).
+  virtual const std::vector<GURL>& GetRedirectChain() = 0;
+
+  enum State {
+    kWaitingResponse,
+    kReceivingBytes,
+    kComplete,
+    kFailed,
+  };
+
+  virtual State GetState() = 0;
+};
+
+}  // namespace weblayer
+
+#endif  // WEBLAYER_PUBLIC_NAVIGATION_H_

weblayer/public/navigation_observer.h

+// Copyright 2019 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 WEBLAYER_PUBLIC_NAVIGATION_OBSERVER_H_
+#define WEBLAYER_PUBLIC_NAVIGATION_OBSERVER_H_
+
+#include <algorithm>
+
+namespace weblayer {
+class Navigation;
+
+// The lifecycle of a navigation:
+// 1) NavigationStarted
+// 2) 0 or more NavigationRedirected
+// 3) 0 or 1 NavigationCommitted
+// 3) 0 or 1 NavigationHadFirstContentfulPaint
+// 4) NavigationCompleted or NavigationFailed
+class NavigationObserver {
+ public:
+  virtual ~NavigationObserver() {}
+
+  virtual void NavigationStarted(Navigation* navigation) = 0;
+
+  virtual void NavigationRedirected(Navigation* navigation) = 0;
+
+  virtual void NavigationCommitted(Navigation* navigation) = 0;
+
+  virtual void NavigationHadFirstContentfulPaint(Navigation* navigation) = 0;
+
+  virtual void NavigationCompleted(Navigation* navigation) = 0;
+
+  virtual void NavigationFailed(Navigation* navigation) = 0;
+};
+
+}  // namespace weblayer
+
+#endif  // WEBLAYER_PUBLIC_NAVIGATION_OBSERVER_H_