Keep top controls visible if SHOW is called right after HIDE.

cc/input/top_controls_manager_unittest.cc

 // Copyright 2013 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 "cc/input/top_controls_manager.h"
 
 #include <algorithm>
 #include <cmath>
 #include <memory>
 
@@ skipping 494 matching lines @@
   EXPECT_FLOAT_EQ(0.f, manager->BottomControlsShownRatio());
   manager->ScrollEnd();
 
   manager->ScrollBegin();
   manager->ScrollBy(gfx::Vector2dF(0.f, -15.f));
   EXPECT_FLOAT_EQ(15.f, manager->ContentBottomOffset());
   EXPECT_FLOAT_EQ(0.15f, manager->BottomControlsShownRatio());
   manager->ScrollEnd();
 }
 
+TEST(TopControlsManagerTest, HideAndImmediateShowKeepsControlsVisible) {
+  MockTopControlsManagerClient client(100.f, 0.5f, 0.5f);
+  client.SetBottomControlsHeight(100.f);
+  TopControlsManager* manager = client.manager();
+  EXPECT_FLOAT_EQ(1.f, client.CurrentTopControlsShownRatio());
+
+  manager->UpdateTopControlsState(BOTH, HIDDEN, true);
+  EXPECT_TRUE(manager->has_animation());
+  EXPECT_FLOAT_EQ(1.f, client.CurrentTopControlsShownRatio());
+
+  manager->UpdateTopControlsState(BOTH, SHOWN, true);
+  EXPECT_FALSE(manager->has_animation());
+  EXPECT_FLOAT_EQ(1.f, client.CurrentTopControlsShownRatio());
+}
+
 }  // namespace
 }  // namespace cc