Mac: Delete now-dead elastic overscroll code

Source/platform/mac/ScrollElasticityControllerTest.mm

-// 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 "config.h"
-#include <gtest/gtest.h>
-
-#include "platform/geometry/IntPoint.h"
-#include "platform/geometry/IntSize.h"
-#include "platform/mac/ScrollElasticityController.h"
-#include "platform/PlatformWheelEvent.h"
-
-namespace blink {
-
-class MockScrollElasticityControllerClient : public ScrollElasticityControllerClient {
-public:
-    MockScrollElasticityControllerClient() : m_pinned(true), m_stretchX(0.0f) {}
-
-    virtual bool allowsHorizontalStretching() override { return true; }
-    virtual bool allowsVerticalStretching() override { return true; }
-    // The amount that the view is stretched past the normal allowable bounds.
-    // The "overhang" amount.
-    virtual IntSize stretchAmount() override { return IntSize(m_stretchX, 0); }
-    virtual bool pinnedInDirection(const FloatSize&) override { return m_pinned; }
-    virtual bool canScrollHorizontally() override { return true; }
-    virtual bool canScrollVertically() override { return true; }
-
-    // Return the absolute scroll position, not relative to the scroll origin.
-    virtual IntPoint absoluteScrollPosition() override { return IntPoint(m_stretchX, 0); }
-
-    virtual void immediateScrollBy(const FloatSize& size) override { m_stretchX += size.width(); }
-    virtual void immediateScrollByWithoutContentEdgeConstraints(const FloatSize& size) override { m_stretchX += size.width(); }
-    virtual void startSnapRubberbandTimer() override {}
-    virtual void stopSnapRubberbandTimer() override {}
-    virtual void adjustScrollPositionToBoundsIfNecessary() override {}
-
-    void reset() { m_stretchX = 0; }
-
-    bool m_pinned;
-
-private:
-    float m_stretchX;
-};
-
-class MockPlatformWheelEvent : public PlatformWheelEvent {
-public:
-    MockPlatformWheelEvent(PlatformWheelEventPhase phase, float deltaX, bool canRubberbandLeft)
-    {
-        m_phase = phase;
-        m_deltaX = deltaX;
-        m_canRubberbandLeft = canRubberbandLeft;
-    }
-};
-
-enum RubberbandPermission {
-    DisallowRubberband,
-    AllowRubberband
-};
-
-enum ScrollPermission {
-    DisallowScroll,
-    AllowScroll
-};
-
-const float deltaLeft = 1.0f;
-const float deltaNone = 0.0f;
-
-class ScrollElasticityControllerTest : public testing::Test {
-public:
-    ScrollElasticityControllerTest() : m_controller(&m_client) {}
-
-    // Makes a wheel event with the given parameters, and forwards the event to the
-    // controller.
-    bool handleWheelEvent(RubberbandPermission canRubberband, ScrollPermission canScroll, PlatformWheelEventPhase phase, float delta)
-    {
-        m_client.m_pinned = !canScroll;
-        MockPlatformWheelEvent event(phase, delta, canRubberband);
-        return m_controller.handleWheelEvent(event);
-    }
-
-    void SetUp()
-    {
-        m_client.reset();
-    }
-
-private:
-    MockScrollElasticityControllerClient m_client;
-    ScrollElasticityController m_controller;
-};
-
-// The client cannot scroll, but the event allows rubber banding.
-TEST_F(ScrollElasticityControllerTest, canRubberband)
-{
-    // The PlatformWheelEventPhaseMayBegin event should never be handled.
-    EXPECT_FALSE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseMayBegin, deltaNone));
-
-    // All other events should be handled.
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseBegan, deltaLeft));
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseChanged, deltaLeft));
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseEnded, deltaNone));
-}
-
-// The client cannot scroll, and the event disallows rubber banding.
-TEST_F(ScrollElasticityControllerTest, cannotRubberband)
-{
-    // The PlatformWheelEventPhaseMayBegin event should never be handled.
-    EXPECT_FALSE(handleWheelEvent(DisallowRubberband, DisallowScroll, PlatformWheelEventPhaseMayBegin, deltaNone));
-
-    // Rubber-banding is disabled, and the client is pinned.
-    // Ignore all events.
-    EXPECT_FALSE(handleWheelEvent(DisallowRubberband, DisallowScroll, PlatformWheelEventPhaseBegan, deltaLeft));
-    EXPECT_FALSE(handleWheelEvent(DisallowRubberband, DisallowScroll, PlatformWheelEventPhaseChanged, deltaLeft));
-    EXPECT_FALSE(handleWheelEvent(DisallowRubberband, DisallowScroll, PlatformWheelEventPhaseEnded, deltaNone));
-}
-
-// The client can scroll, and the event disallows rubber banding.
-TEST_F(ScrollElasticityControllerTest, cannotRubberbandCanScroll)
-{
-    // The PlatformWheelEventPhaseMayBegin event should never be handled.
-    EXPECT_FALSE(handleWheelEvent(DisallowRubberband, AllowScroll, PlatformWheelEventPhaseMayBegin, deltaNone));
-
-    // Rubber-banding is disabled, but the client is not pinned.
-    // Handle all events.
-    EXPECT_TRUE(handleWheelEvent(DisallowRubberband, AllowScroll, PlatformWheelEventPhaseBegan, deltaLeft));
-    EXPECT_TRUE(handleWheelEvent(DisallowRubberband, AllowScroll, PlatformWheelEventPhaseChanged, deltaLeft));
-    EXPECT_TRUE(handleWheelEvent(DisallowRubberband, AllowScroll, PlatformWheelEventPhaseEnded, deltaNone));
-}
-
-// The client cannot scroll. The initial events allow rubber banding, but the
-// later events disallow it.
-TEST_F(ScrollElasticityControllerTest, canRubberbandBecomesFalse)
-{
-    // The PlatformWheelEventPhaseMayBegin event should never be handled.
-    EXPECT_FALSE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseMayBegin, deltaNone));
-
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseBegan, deltaLeft));
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseChanged, deltaLeft));
-
-    // Rubber-banding is no longer allowed, but its already started.
-    // Events should still be handled.
-    EXPECT_TRUE(handleWheelEvent(DisallowRubberband, DisallowScroll, PlatformWheelEventPhaseChanged, deltaLeft));
-    EXPECT_TRUE(handleWheelEvent(DisallowRubberband, DisallowScroll, PlatformWheelEventPhaseEnded, deltaNone));
-}
-
-// The client cannot scroll. The initial events disallow rubber banding, but the
-// later events allow it.
-TEST_F(ScrollElasticityControllerTest, canRubberbandBecomesTrue)
-{
-    // The PlatformWheelEventPhaseMayBegin event should never be handled.
-    EXPECT_FALSE(handleWheelEvent(DisallowRubberband, DisallowScroll, PlatformWheelEventPhaseMayBegin, deltaNone));
-
-    EXPECT_FALSE(handleWheelEvent(DisallowRubberband, DisallowScroll, PlatformWheelEventPhaseBegan, deltaLeft));
-    EXPECT_FALSE(handleWheelEvent(DisallowRubberband, DisallowScroll, PlatformWheelEventPhaseChanged, deltaLeft));
-
-    // Rubber-banding is now allowed
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseChanged, deltaLeft));
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseEnded, deltaNone));
-}
-
-// Events with no delta should not cause scrolling.
-TEST_F(ScrollElasticityControllerTest, zeroDeltaEventsIgnored)
-{
-    // The PlatformWheelEventPhaseMayBegin event should never be handled.
-    EXPECT_FALSE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseMayBegin, deltaNone));
-
-    // TODO(erikchen): This logic is incorrect. The zero delta event should not have been handled. crbug.com/375512
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseBegan, deltaNone));
-    EXPECT_FALSE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseChanged, deltaNone));
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseChanged, deltaLeft));
-    EXPECT_TRUE(handleWheelEvent(AllowRubberband, DisallowScroll, PlatformWheelEventPhaseEnded, deltaNone));
-}
-
-} // namespace blink