Gesture Nav: Protect against the case when navigation completes as soon as it is requested.

content/browser/web_contents/aura/overscroll_navigation_overlay_unittest.cc

 // Copyright 2014 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.
 
 #include "content/browser/web_contents/aura/overscroll_navigation_overlay.h"
 
 #include <string.h>
 #include <utility>
 #include <vector>
 
@@ skipping 13 matching lines @@
 #include "ui/aura_extra/image_window_delegate.h"
 #include "ui/compositor/scoped_animation_duration_scale_mode.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/compositor/test/layer_animator_test_controller.h"
 #include "ui/events/gesture_detection/gesture_configuration.h"
 #include "ui/events/test/event_generator.h"
 #include "ui/gfx/codec/png_codec.h"
 
 namespace content {
 
+// Forces web contents to complete web page load as soon as navigation starts.
+class ImmediateLoadObserver : WebContentsObserver {
+ public:
+  explicit ImmediateLoadObserver(TestWebContents* contents)
+      : contents_(contents) {
+    Observe(contents);
+  }
+  ~ImmediateLoadObserver() override {}
+
+  void DidStartNavigationToPendingEntry(
+      const GURL& url,
+      NavigationController::ReloadType reload_type) override {
+    // Simulate immediate web page load.
+    contents_->TestSetIsLoading(false);
+    Observe(nullptr);
+  }
+
+ private:
+  TestWebContents* contents_;
+
+  DISALLOW_COPY_AND_ASSIGN(ImmediateLoadObserver);
+};
+
 // A subclass of TestWebContents that offers a fake content window.
 class OverscrollTestWebContents : public TestWebContents {
  public:
   ~OverscrollTestWebContents() override {}
 
   static OverscrollTestWebContents* Create(
       BrowserContext* browser_context,
       scoped_refptr<SiteInstance> instance,
       std::unique_ptr<aura::Window> fake_native_view,
       std::unique_ptr<aura::Window> fake_contents_window) {
@@ skipping 280 matching lines @@
   GetOverlay()->owa_->OnOverscrollComplete(OVERSCROLL_EAST);
   EXPECT_EQ(GetOverlay()->direction_, OverscrollNavigationOverlay::BACK);
   OverscrollTestWebContents* test_web_contents =
       static_cast<OverscrollTestWebContents*>(web_contents());
   test_web_contents->set_is_being_destroyed(true);
   test_web_contents->ResetContentNativeView();
   test_web_contents->ResetNativeView();
   // Ensure a clean close.
 }
 
+// Tests that we can handle the case when the load completes as soon as the
+// navigation is started.
+TEST_F(OverscrollNavigationOverlayTest, ImmediateLoadOnNavigate) {
+  PerformBackNavigationViaSliderCallbacks();
+  // This observer will force the page load to complete as soon as the
+  // navigation starts.
+  ImmediateLoadObserver immediate_nav(contents());
+  GetOverlay()->owa_->OnOverscrollModeChange(OVERSCROLL_NONE, OVERSCROLL_EAST);
+  // This will start and immediately complete the navigation.
+  GetOverlay()->owa_->OnOverscrollComplete(OVERSCROLL_EAST);
+  EXPECT_FALSE(GetOverlay()->window_.get());
+}
 
 // Tests that swapping the overlay window at the end of a gesture caused by the
 // start of a new overscroll does not crash and the events still reach the new
 // overlay window.
 TEST_F(OverscrollNavigationOverlayTest, OverlayWindowSwap) {
   PerformBackNavigationViaSliderCallbacks();
   aura::Window* first_overlay_window = GetOverlay()->window_.get();
   EXPECT_TRUE(GetOverlay()->web_contents());
   EXPECT_TRUE(first_overlay_window);
 
@@ skipping 62 matching lines @@
   EXPECT_TRUE(GetOverlay()->window_.get());
 
   // Load the page.
   contents()->CommitPendingNavigation();
   ReceivePaintUpdate();
   EXPECT_FALSE(GetOverlay()->window_.get());
   EXPECT_EQ(contents()->GetURL(), first());
 }
 
 }  // namespace content