Bug 1150810 part 4 - Store global on Animation; r=smaug, jwatt

The connection between an Animation and an AnimationTimeline is optional. That
is, it is possible to have an Animation without an AnimationTimeline. Until now
we have often just assumed the timeline will be set but eventually we need to
support the possibility of the timeline being null. Indeed, later in this patch
series we will set the timeline out-of-band (i.e. not in the constructor) using
SetTimeline which opens up the possibility that timeline will be null for
a period of time.

This patch paves the way for having an optional timeline by storing the global
used for, e.g. creating promises, on the Animation object itself.

dom/animation/Animation.cpp

@@ -21,7 +21,7 @@ namespace dom {
 // Static members
 uint64_t Animation::sNextSequenceNum = 0;
 
-NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(Animation, mTimeline,
+NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE(Animation, mGlobal, mTimeline,
                                       mEffect, mReady, mFinished)
 NS_IMPL_CYCLE_COLLECTING_ADDREF(Animation)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(Animation)
@@ -173,21 +173,11 @@ Animation::PlayState() const
   return AnimationPlayState::Running;
 }
 
-static inline already_AddRefed<Promise>
-CreatePromise(AnimationTimeline* aTimeline, ErrorResult& aRv)
-{
-  nsIGlobalObject* global = aTimeline->GetParentObject();
-  if (global) {
-    return Promise::Create(global, aRv);
-  }
-  return nullptr;
-}
-
 Promise*
 Animation::GetReady(ErrorResult& aRv)
 {
-  if (!mReady) {
-    mReady = CreatePromise(mTimeline, aRv); // Lazily create on demand
+  if (!mReady && mGlobal) {
+    mReady = Promise::Create(mGlobal, aRv); // Lazily create on demand
   }
   if (!mReady) {
     aRv.Throw(NS_ERROR_FAILURE);
@@ -200,8 +190,8 @@ Animation::GetReady(ErrorResult& aRv)
 Promise*
 Animation::GetFinished(ErrorResult& aRv)
 {
-  if (!mFinished) {
-    mFinished = CreatePromise(mTimeline, aRv); // Lazily create on demand
+  if (!mFinished && mGlobal) {
+    mFinished = Promise::Create(mGlobal, aRv); // Lazily create on demand
   }
   if (!mFinished) {
     aRv.Throw(NS_ERROR_FAILURE);

dom/animation/Animation.h

@@ -16,6 +16,7 @@
 #include "mozilla/dom/KeyframeEffect.h" // for KeyframeEffectReadOnly
 #include "mozilla/dom/Promise.h" // for Promise
 #include "nsCSSProperty.h" // for nsCSSProperty
+#include "nsIGlobalObject.h"
 
 // X11 has a #define for CurrentTime.
 #ifdef CurrentTime
@@ -53,8 +54,9 @@ protected:
   virtual ~Animation() {}
 
 public:
-  explicit Animation(AnimationTimeline* aTimeline)
-    : mTimeline(aTimeline)
+  explicit Animation(nsIGlobalObject* aGlobal, AnimationTimeline* aTimeline)
+    : mGlobal(aGlobal)
+    , mTimeline(aTimeline)
     , mPlaybackRate(1.0)
     , mPendingState(PendingState::NotPending)
     , mSequenceNum(kUnsequenced)
@@ -339,6 +341,7 @@ protected:
   virtual css::CommonAnimationManager* GetAnimationManager() const = 0;
   AnimationCollection* GetCollection() const;
 
+  nsCOMPtr<nsIGlobalObject> mGlobal;
   nsRefPtr<AnimationTimeline> mTimeline;
   nsRefPtr<KeyframeEffectReadOnly> mEffect;
   // The beginning of the delay period.

layout/style/nsAnimationManager.cpp

@@ -598,7 +598,9 @@ nsAnimationManager::BuildAnimations(nsStyleContext* aStyleContext,
       continue;
     }
 
-    nsRefPtr<CSSAnimation> dest = new CSSAnimation(aTimeline, src.GetName());
+    nsRefPtr<CSSAnimation> dest =
+      new CSSAnimation(mPresContext->Document()->GetScopeObject(), aTimeline,
+                       src.GetName());
     dest->SetOwningElement(
       OwningElementRef(*aTarget, aStyleContext->GetPseudoType()));
     dest->SetAnimationIndex(static_cast<uint64_t>(animIdx));

layout/style/nsAnimationManager.h

@@ -13,6 +13,7 @@
 #include "mozilla/MemoryReporting.h"
 #include "mozilla/TimeStamp.h"
 
+class nsIGlobalObject;
 class nsStyleContext;
 
 namespace mozilla {
@@ -56,9 +57,10 @@ namespace dom {
 class CSSAnimation final : public Animation
 {
 public:
- explicit CSSAnimation(dom::AnimationTimeline* aTimeline,
+ explicit CSSAnimation(nsIGlobalObject* aGlobal,
+                       dom::AnimationTimeline* aTimeline,
                        const nsSubstring& aAnimationName)
-    : dom::Animation(aTimeline)
+    : dom::Animation(aGlobal, aTimeline)
     , mAnimationName(aAnimationName)
     , mIsStylePaused(false)
     , mPauseShouldStick(false)

layout/style/nsTransitionManager.cpp

@@ -632,7 +632,8 @@ nsTransitionManager::ConsiderStartingTransition(
   segment.mToKey = 1;
   segment.mTimingFunction.Init(tf);
 
-  nsRefPtr<CSSTransition> animation = new CSSTransition(timeline);
+  nsRefPtr<CSSTransition> animation =
+    new CSSTransition(mPresContext->Document()->GetScopeObject(), timeline);
   animation->SetOwningElement(
     OwningElementRef(*aElement, aNewStyleContext->GetPseudoType()));
   animation->SetCreationSequence(

layout/style/nsTransitionManager.h

@@ -15,6 +15,7 @@
 #include "AnimationCommon.h"
 #include "nsCSSPseudoElements.h"
 
+class nsIGlobalObject;
 class nsStyleContext;
 class nsPresContext;
 class nsCSSPropertySet;
@@ -79,8 +80,9 @@ namespace dom {
 class CSSTransition final : public Animation
 {
 public:
- explicit CSSTransition(dom::AnimationTimeline* aTimeline)
-    : dom::Animation(aTimeline)
+ explicit CSSTransition(nsIGlobalObject* aGlobal,
+                        dom::AnimationTimeline* aTimeline)
+    : dom::Animation(aGlobal, aTimeline)
   {
   }