Revert of Improve performance of GeometryMapper cache.

third_party/WebKit/Source/platform/graphics/paint/GeometryMapperClipCache.cpp

-// 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.
-
-#include "platform/graphics/paint/GeometryMapperClipCache.h"
-
-#include "platform/graphics/paint/FloatClipRect.h"
-
-namespace blink {
-
-// All clip caches invalidate themselves by tracking a local cache generation,
-// and invalidating their cache if their cache generation disagrees with
-// s_clipCacheGeneration.
-static unsigned s_clipCacheGeneration = 0;
-
-void GeometryMapperClipCache::clearCache() {
-  s_clipCacheGeneration++;
-}
-
-void GeometryMapperClipCache::invalidateCacheIfNeeded() {
-  if (m_cacheGeneration != s_clipCacheGeneration) {
-    m_clipCache.clear();
-    m_cacheGeneration = s_clipCacheGeneration;
-  }
-}
-
-const FloatClipRect* GeometryMapperClipCache::getCachedClip(
-    const ClipAndTransform& clipAndTransform) {
-  invalidateCacheIfNeeded();
-  for (const auto& entry : m_clipCache) {
-    if (entry.clipAndTransform == clipAndTransform) {
-      return &entry.clipRect;
-    }
-  }
-  return nullptr;
-}
-
-void GeometryMapperClipCache::setCachedClip(
-    const ClipAndTransform& clipAndTransform,
-    const FloatClipRect& clip) {
-  invalidateCacheIfNeeded();
-#if DCHECK_IS_ON()
-  for (const auto& entry : m_clipCache) {
-    if (entry.clipAndTransform == clipAndTransform)
-      DCHECK(false);  // There should be no existing entry.
-  }
-#endif
-  m_clipCache.push_back(ClipCacheEntry(clipAndTransform, clip));
-}
-
-}  // namespace blink