CC Animation: Extract PropertyAnimationState as a non-nested struct.

cc/animation/property_animation_state.cc

Index: cc/animation/property_animation_state.cc
diff --git a/cc/animation/property_animation_state.cc b/cc/animation/property_animation_state.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1691744b294e5ce0b293ebf4a5d07bcff87ea1b0
--- /dev/null
+++ b/cc/animation/property_animation_state.cc
@@ -0,0 +1,83 @@
+// Copyright 2016 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/animation/property_animation_state.h"
+
+#include "base/logging.h"
+
+namespace cc {
+
+bool PropertyAnimationState::operator==(
+    const PropertyAnimationState& other) const {
+  return currently_running_for_active_elements ==
+             other.currently_running_for_active_elements &&
+         currently_running_for_pending_elements ==
+             other.currently_running_for_pending_elements &&
+         potentially_animating_for_active_elements ==
+             other.potentially_animating_for_active_elements &&
+         potentially_animating_for_pending_elements ==
+             other.potentially_animating_for_pending_elements;
+}
+
+bool PropertyAnimationState::operator!=(
+    const PropertyAnimationState& other) const {
+  return !operator==(other);
+}
+
+PropertyAnimationState& PropertyAnimationState::operator|=(
+    const PropertyAnimationState& other) {
+  currently_running_for_active_elements |=
+      other.currently_running_for_active_elements;
+  currently_running_for_pending_elements |=
+      other.currently_running_for_pending_elements;
+  potentially_animating_for_active_elements |=
+      other.potentially_animating_for_active_elements;
+  potentially_animating_for_pending_elements |=
+      other.potentially_animating_for_pending_elements;
+
+  return *this;
+}
+
+PropertyAnimationState& PropertyAnimationState::operator^=(
+    const PropertyAnimationState& other) {
+  currently_running_for_active_elements ^=
+      other.currently_running_for_active_elements;
+  currently_running_for_pending_elements ^=
+      other.currently_running_for_pending_elements;
+  potentially_animating_for_active_elements ^=
+      other.potentially_animating_for_active_elements;
+  potentially_animating_for_pending_elements ^=
+      other.potentially_animating_for_pending_elements;
+
+  return *this;
+}
+
+PropertyAnimationState operator^(const PropertyAnimationState& lhs,
+                                 const PropertyAnimationState& rhs) {
+  PropertyAnimationState result = lhs;
+  result ^= rhs;
+  return result;
+}
+
+bool PropertyAnimationState::IsValid() const {
+  // currently_running must be a subset for potentially_animating.
+  // currently <= potentially.
+  DCHECK_LE(currently_running_for_active_elements,
+            potentially_animating_for_active_elements);
+  DCHECK_LE(currently_running_for_pending_elements,
+            potentially_animating_for_pending_elements);
+  return currently_running_for_active_elements <=

[ajuma, 2016/09/16 16:50:52]

Code after a DCHECK should assume that the DCHECK holds (see
https://chromium.googlesource.com/chromium/src/+/master/styleguide/c++/c++.md...),
so I'd suggest removing these DCHECKs and depending on callers to DCHECK the
return value (and they already do that).

[loyso (OOO), 2016/09/19 02:45:35]

Done.

+             potentially_animating_for_active_elements &&
+         currently_running_for_pending_elements <=
+             potentially_animating_for_pending_elements;
+}
+
+void PropertyAnimationState::Clear() {
+  currently_running_for_active_elements = false;
+  currently_running_for_pending_elements = false;
+  potentially_animating_for_active_elements = false;
+  potentially_animating_for_pending_elements = false;
+}
+
+}  // namespace cc