diff --git a/layout/style/nsAnimationManager.cpp b/layout/style/nsAnimationManager.cpp
index 101af476a45..ad5ae371629 100644
--- a/layout/style/nsAnimationManager.cpp
+++ b/layout/style/nsAnimationManager.cpp
@@ -14,110 +14,13 @@
 
 using namespace mozilla;
 
-struct AnimationPropertySegment
+ElementAnimations::ElementAnimations(mozilla::dom::Element *aElement, nsIAtom *aElementProperty,
+                                     nsAnimationManager *aAnimationManager)
+  : CommonElementAnimationData(aElement, aElementProperty,
+                               aAnimationManager),
+    mNeedsRefreshes(true)
 {
-  float mFromKey, mToKey;
-  nsStyleAnimation::Value mFromValue, mToValue;
-  css::ComputedTimingFunction mTimingFunction;
-};
-
-struct AnimationProperty
-{
-  nsCSSProperty mProperty;
-  InfallibleTArray<AnimationPropertySegment> mSegments;
-};
-
-/**
- * Data about one animation (i.e., one of the values of
- * 'animation-name') running on an element.
- */
-struct ElementAnimation
-{
-  ElementAnimation()
-    : mLastNotification(LAST_NOTIFICATION_NONE)
-  {
-  }
-
-  nsString mName; // empty string for 'none'
-  float mIterationCount; // NS_IEEEPositiveInfinity() means infinite
-  PRUint8 mDirection;
-  PRUint8 mFillMode;
-  PRUint8 mPlayState;
-
-  bool FillsForwards() const {
-    return mFillMode == NS_STYLE_ANIMATION_FILL_MODE_BOTH ||
-           mFillMode == NS_STYLE_ANIMATION_FILL_MODE_FORWARDS;
-  }
-  bool FillsBackwards() const {
-    return mFillMode == NS_STYLE_ANIMATION_FILL_MODE_BOTH ||
-           mFillMode == NS_STYLE_ANIMATION_FILL_MODE_BACKWARDS;
-  }
-
-  bool IsPaused() const {
-    return mPlayState == NS_STYLE_ANIMATION_PLAY_STATE_PAUSED;
-  }
-
-  TimeStamp mStartTime; // with delay taken into account
-  TimeStamp mPauseStart;
-  TimeDuration mIterationDuration;
-
-  enum {
-    LAST_NOTIFICATION_NONE = PRUint32(-1),
-    LAST_NOTIFICATION_END = PRUint32(-2)
-  };
-  // One of the above constants, or an integer for the iteration
-  // whose start we last notified on.
-  PRUint32 mLastNotification;
-
-  InfallibleTArray<AnimationProperty> mProperties;
-};
-
-typedef nsAnimationManager::EventArray EventArray;
-typedef nsAnimationManager::AnimationEventInfo AnimationEventInfo;
-
-/**
- * Data about all of the animations running on an element.
- */
-struct ElementAnimations : public mozilla::css::CommonElementAnimationData
-{
-  ElementAnimations(dom::Element *aElement, nsIAtom *aElementProperty,
-                     nsAnimationManager *aAnimationManager)
-    : CommonElementAnimationData(aElement, aElementProperty,
-                                 aAnimationManager),
-      mNeedsRefreshes(true)
-  {
-  }
-
-  void EnsureStyleRuleFor(TimeStamp aRefreshTime,
-                          EventArray &aEventsToDispatch);
-
-  bool IsForElement() const { // rather than for a pseudo-element
-    return mElementProperty == nsGkAtoms::animationsProperty;
-  }
-
-  void PostRestyleForAnimation(nsPresContext *aPresContext) {
-    nsRestyleHint hint = IsForElement() ? eRestyle_Self : eRestyle_Subtree;
-    aPresContext->PresShell()->RestyleForAnimation(mElement, hint);
-  }
-
-  // This style rule contains the style data for currently animating
-  // values.  It only matches when styling with animation.  When we
-  // style without animation, we need to not use it so that we can
-  // detect any new changes; if necessary we restyle immediately
-  // afterwards with animation.
-  // NOTE: If we don't need to apply any styles, mStyleRule will be
-  // null, but mStyleRuleRefreshTime will still be valid.
-  nsRefPtr<css::AnimValuesStyleRule> mStyleRule;
-  // The refresh time associated with mStyleRule.
-  TimeStamp mStyleRuleRefreshTime;
-
-  // False when we know that our current style rule is valid
-  // indefinitely into the future (because all of our animations are
-  // either completed or paused).  May be invalidated by a style change.
-  bool mNeedsRefreshes;
-
-  InfallibleTArray<ElementAnimation> mAnimations;
-};
+}
 
 static void
 ElementAnimationsPropertyDtor(void           *aObject,
diff --git a/layout/style/nsAnimationManager.h b/layout/style/nsAnimationManager.h
index fb7733c98e5..af873c495a3 100644
--- a/layout/style/nsAnimationManager.h
+++ b/layout/style/nsAnimationManager.h
@@ -14,9 +14,6 @@
 #include "nsThreadUtils.h"
 
 class nsCSSKeyframesRule;
-struct AnimationPropertySegment;
-struct ElementAnimation;
-struct ElementAnimations;
 
 namespace mozilla {
 namespace css {
@@ -24,6 +21,130 @@ class Declaration;
 }
 }
 
+struct AnimationEventInfo {
+  nsRefPtr<mozilla::dom::Element> mElement;
+  nsAnimationEvent mEvent;
+
+  AnimationEventInfo(mozilla::dom::Element *aElement,
+                     const nsString& aAnimationName,
+                     PRUint32 aMessage, mozilla::TimeDuration aElapsedTime)
+    : mElement(aElement),
+      mEvent(true, aMessage, aAnimationName, aElapsedTime.ToSeconds())
+  {
+  }
+
+  // nsAnimationEvent doesn't support copy-construction, so we need
+  // to ourselves in order to work with nsTArray
+  AnimationEventInfo(const AnimationEventInfo &aOther)
+    : mElement(aOther.mElement),
+      mEvent(true, aOther.mEvent.message,
+             aOther.mEvent.animationName, aOther.mEvent.elapsedTime)
+  {
+  }
+};
+
+typedef InfallibleTArray<AnimationEventInfo> EventArray;
+
+struct AnimationPropertySegment
+{
+  float mFromKey, mToKey;
+  nsStyleAnimation::Value mFromValue, mToValue;
+  mozilla::css::ComputedTimingFunction mTimingFunction;
+};
+
+struct AnimationProperty
+{
+  nsCSSProperty mProperty;
+  InfallibleTArray<AnimationPropertySegment> mSegments;
+};
+
+/**
+ * Data about one animation (i.e., one of the values of
+ * 'animation-name') running on an element.
+ */
+struct ElementAnimation
+{
+  ElementAnimation()
+    : mLastNotification(LAST_NOTIFICATION_NONE)
+  {
+  }
+
+  nsString mName; // empty string for 'none'
+  float mIterationCount; // NS_IEEEPositiveInfinity() means infinite
+  PRUint8 mDirection;
+  PRUint8 mFillMode;
+  PRUint8 mPlayState;
+
+  bool FillsForwards() const {
+    return mFillMode == NS_STYLE_ANIMATION_FILL_MODE_BOTH ||
+           mFillMode == NS_STYLE_ANIMATION_FILL_MODE_FORWARDS;
+  }
+  bool FillsBackwards() const {
+    return mFillMode == NS_STYLE_ANIMATION_FILL_MODE_BOTH ||
+           mFillMode == NS_STYLE_ANIMATION_FILL_MODE_BACKWARDS;
+  }
+
+  bool IsPaused() const {
+    return mPlayState == NS_STYLE_ANIMATION_PLAY_STATE_PAUSED;
+  }
+
+  mozilla::TimeStamp mStartTime; // with delay taken into account
+  mozilla::TimeStamp mPauseStart;
+  mozilla::TimeDuration mIterationDuration;
+
+  enum {
+    LAST_NOTIFICATION_NONE = PRUint32(-1),
+    LAST_NOTIFICATION_END = PRUint32(-2)
+  };
+  // One of the above constants, or an integer for the iteration
+  // whose start we last notified on.
+  PRUint32 mLastNotification;
+
+  InfallibleTArray<AnimationProperty> mProperties;
+};
+
+/**
+ * Data about all of the animations running on an element.
+ */
+struct ElementAnimations : public mozilla::css::CommonElementAnimationData
+{
+  typedef mozilla::TimeStamp TimeStamp;
+  typedef mozilla::TimeDuration TimeDuration;
+
+  ElementAnimations(mozilla::dom::Element *aElement, nsIAtom *aElementProperty,
+                    nsAnimationManager *aAnimationManager);
+
+  void EnsureStyleRuleFor(TimeStamp aRefreshTime,
+                          EventArray &aEventsToDispatch);
+
+  bool IsForElement() const { // rather than for a pseudo-element
+    return mElementProperty == nsGkAtoms::animationsProperty;
+  }
+
+  void PostRestyleForAnimation(nsPresContext *aPresContext) {
+    nsRestyleHint styleHint = IsForElement() ? eRestyle_Self : eRestyle_Subtree;
+    aPresContext->PresShell()->RestyleForAnimation(mElement, styleHint);
+  }
+
+  // This style rule contains the style data for currently animating
+  // values.  It only matches when styling with animation.  When we
+  // style without animation, we need to not use it so that we can
+  // detect any new changes; if necessary we restyle immediately
+  // afterwards with animation.
+  // NOTE: If we don't need to apply any styles, mStyleRule will be
+  // null, but mStyleRuleRefreshTime will still be valid.
+  nsRefPtr<mozilla::css::AnimValuesStyleRule> mStyleRule;
+  // The refresh time associated with mStyleRule.
+  TimeStamp mStyleRuleRefreshTime;
+
+  // False when we know that our current style rule is valid
+  // indefinitely into the future (because all of our animations are
+  // either completed or paused).  May be invalidated by a style change.
+  bool mNeedsRefreshes;
+
+  InfallibleTArray<ElementAnimation> mAnimations;
+};
+
 class nsAnimationManager : public mozilla::css::CommonAnimationManager
 {
 public:
@@ -34,27 +155,8 @@ public:
     mKeyframesRules.Init(16); // FIXME: make infallible!
   }
 
-  struct AnimationEventInfo {
-    nsRefPtr<mozilla::dom::Element> mElement;
-    nsAnimationEvent mEvent;
 
-    AnimationEventInfo(mozilla::dom::Element *aElement,
-                       const nsString& aAnimationName,
-                       PRUint32 aMessage, mozilla::TimeDuration aElapsedTime)
-      : mElement(aElement),
-        mEvent(true, aMessage, aAnimationName, aElapsedTime.ToSeconds())
-    {
-    }
 
-    // nsAnimationEvent doesn't support copy-construction, so we need
-    // to ourselves in order to work with nsTArray
-    AnimationEventInfo(const AnimationEventInfo &aOther)
-      : mElement(aOther.mElement),
-        mEvent(true, aOther.mEvent.message,
-               aOther.mEvent.animationName, aOther.mEvent.elapsedTime)
-    {
-    }
-  };
 
   // nsIStyleRuleProcessor (parts)
   virtual void RulesMatching(ElementRuleProcessorData* aData);
@@ -89,8 +191,6 @@ public:
     mKeyframesListIsDirty = true;
   }
 
-  typedef InfallibleTArray<AnimationEventInfo> EventArray;
-
   /**
    * Dispatch any pending events.  We accumulate animationend and
    * animationiteration events only during refresh driver notifications