--- a/dom/animation/KeyframeEffectReadOnly.cpp
+++ b/dom/animation/KeyframeEffectReadOnly.cpp
@@ -13,17 +13,17 @@
 #include "mozilla/AnimationRule.h"
 #include "mozilla/AnimationUtils.h"
 #include "mozilla/AutoRestore.h"
 #include "mozilla/EffectSet.h"
 #include "mozilla/FloatingPoint.h" // For IsFinite
 #include "mozilla/LookAndFeel.h" // For LookAndFeel::GetInt
 #include "mozilla/KeyframeUtils.h"
 #include "mozilla/ServoBindings.h"
-#include "mozilla/StyleAnimationValue.h"
+#include "mozilla/StyleAnimationValueInlines.h"
 #include "Layers.h" // For Layer
 #include "nsComputedDOMStyle.h" // nsComputedDOMStyle::GetStyleContextForElement
 #include "nsContentUtils.h"  // nsContentUtils::ReportToConsole
 #include "nsCSSPropertyIDSet.h"
 #include "nsCSSProps.h" // For nsCSSProps::PropHasFlags
 #include "nsCSSPseudoElements.h" // For CSSPseudoElementType
 #include "nsIPresShell.h"
 #include "nsIScriptError.h"

--- a/layout/base/nsLayoutUtils.cpp
+++ b/layout/base/nsLayoutUtils.cpp
@@ -111,16 +111,17 @@
 #include "nsFrameSelection.h"
 #include "FrameLayerBuilder.h"
 #include "mozilla/layers/APZCTreeManager.h"
 #include "mozilla/layers/CompositorBridgeChild.h"
 #include "mozilla/Telemetry.h"
 #include "mozilla/EventDispatcher.h"
 #include "mozilla/EventStateManager.h"
 #include "mozilla/RuleNodeCacheConditions.h"
+#include "mozilla/StyleAnimationValueInlines.h"
 #include "mozilla/StyleSetHandle.h"
 #include "mozilla/StyleSetHandleInlines.h"
 #include "RegionBuilder.h"
 #include "SVGSVGElement.h"
 
 #ifdef MOZ_XUL
 #include "nsXULPopupManager.h"
 #endif
@@ -9354,9 +9355,9 @@ nsLayoutUtils::ComputeGeometryBox(nsIFra
 }
 
 /* static */ bool
 nsLayoutUtils::HasCSSBoxLayout(nsIFrame* aFrame)
 {
   // Except SVG outer element, all SVG element does not have CSS box layout.
   return !aFrame->IsFrameOfType(nsIFrame::eSVG) ||
           aFrame->GetType() == nsGkAtoms::svgOuterSVGFrame;
-}
\ No newline at end of file
+}

--- a/layout/painting/nsDisplayList.cpp
+++ b/layout/painting/nsDisplayList.cpp
@@ -56,16 +56,17 @@
 #include "mozilla/AnimationUtils.h"
 #include "mozilla/EffectCompositor.h"
 #include "mozilla/EffectSet.h"
 #include "mozilla/EventStates.h"
 #include "mozilla/LookAndFeel.h"
 #include "mozilla/OperatorNewExtensions.h"
 #include "mozilla/PendingAnimationTracker.h"
 #include "mozilla/Preferences.h"
+#include "mozilla/StyleAnimationValueInlines.h"
 #include "mozilla/Telemetry.h"
 #include "mozilla/UniquePtr.h"
 #include "mozilla/Unused.h"
 #include "mozilla/ViewportFrame.h"
 #include "mozilla/gfx/gfxVars.h"
 #include "ActiveLayerTracker.h"
 #include "nsContentUtils.h"
 #include "nsPrintfCString.h"

--- a/layout/style/StyleAnimationValue.h
+++ b/layout/style/StyleAnimationValue.h
@@ -14,17 +14,16 @@
 #include "nsStringFwd.h"
 #include "nsStringBuffer.h"
 #include "nsCoord.h"
 #include "nsColor.h"
 #include "nsCSSProps.h"
 #include "nsCSSValue.h"
 #include "nsStyleCoord.h"
 #include "nsStyleTransformMatrix.h"
-#include "ServoBindings.h"
 
 class nsIFrame;
 class nsStyleContext;
 class gfx3DMatrix;
 struct RawServoDeclarationBlock;
 
 namespace mozilla {
 
@@ -592,47 +591,25 @@ struct AnimationValue
   bool operator==(const AnimationValue& aOther) const
   {
     // FIXME: Bug 1337229: add a deep == impl for RawServoAnimationValue.
     return mGecko == aOther.mGecko && mServo == aOther.mServo;
   }
 
   bool IsNull() const { return mGecko.IsNull() && !mServo; }
 
-  float GetOpacity() const
-  {
-    return mServo ? Servo_AnimationValue_GetOpacity(mServo)
-                  : mGecko.GetFloatValue();
-  }
+  inline float GetOpacity() const;
 
   // Returns the scale for mGecko or mServo, which are calculated with
   // reference to aFrame.
-  gfxSize GetScaleValue(const nsIFrame* aFrame) const
-  {
-    if (mServo) {
-      RefPtr<nsCSSValueSharedList> list;
-      Servo_AnimationValue_GetTransform(mServo, &list);
-      return nsStyleTransformMatrix::GetScaleValue(list, aFrame);
-    }
-    return mGecko.GetScaleValue(aFrame);
-  }
+  inline gfxSize GetScaleValue(const nsIFrame* aFrame) const;
 
   // Uncompute this AnimationValue and then serialize it.
-  void SerializeSpecifiedValue(nsCSSPropertyID aProperty,
-                               nsAString& aString) const
-  {
-    if (mServo) {
-      Servo_AnimationValue_Serialize(mServo, aProperty, &aString);
-      return;
-    }
-
-    DebugOnly<bool> uncomputeResult =
-      StyleAnimationValue::UncomputeValue(aProperty, mGecko, aString);
-    MOZ_ASSERT(uncomputeResult, "failed to uncompute StyleAnimationValue");
-  }
+  inline void SerializeSpecifiedValue(nsCSSPropertyID aProperty,
+                                      nsAString& aString) const;
 };
 
 struct PropertyStyleAnimationValuePair
 {
   nsCSSPropertyID mProperty;
   AnimationValue mValue;
 };
 } // namespace mozilla

new file mode 100644
--- /dev/null
+++ b/layout/style/StyleAnimationValueInlines.h
@@ -0,0 +1,48 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_StyleAnimationValueInlines_h_
+#define mozilla_StyleAnimationValueInlines_h_
+
+#include "mozilla/StyleAnimationValue.h"
+#include "mozilla/ServoBindings.h"
+
+namespace mozilla {
+
+float
+AnimationValue::GetOpacity() const
+{
+  return mServo ? Servo_AnimationValue_GetOpacity(mServo)
+                : mGecko.GetFloatValue();
+}
+
+gfxSize
+AnimationValue::GetScaleValue(const nsIFrame* aFrame) const
+{
+  if (mServo) {
+    RefPtr<nsCSSValueSharedList> list;
+    Servo_AnimationValue_GetTransform(mServo, &list);
+    return nsStyleTransformMatrix::GetScaleValue(list, aFrame);
+  }
+  return mGecko.GetScaleValue(aFrame);
+}
+
+void
+AnimationValue::SerializeSpecifiedValue(nsCSSPropertyID aProperty,
+                                        nsAString& aString) const
+{
+  if (mServo) {
+    Servo_AnimationValue_Serialize(mServo, aProperty, &aString);
+    return;
+  }
+
+  DebugOnly<bool> uncomputeResult =
+    StyleAnimationValue::UncomputeValue(aProperty, mGecko, aString);
+  MOZ_ASSERT(uncomputeResult, "failed to uncompute StyleAnimationValue");
+}
+
+} // namespace mozilla
+
+#endif // mozilla_StyleAnimationValueInlines_h_

--- a/layout/style/moz.build
+++ b/layout/style/moz.build
@@ -104,16 +104,17 @@ EXPORTS.mozilla += [
     'ServoPropPrefList.h',
     'ServoStyleRule.h',
     'ServoStyleSet.h',
     'ServoStyleSheet.h',
     'ServoTypes.h',
     'ServoUtils.h',
     'SheetType.h',
     'StyleAnimationValue.h',
+    'StyleAnimationValueInlines.h',
     'StyleBackendType.h',
     'StyleComplexColor.h',
     'StyleContextSource.h',
     'StyleSetHandle.h',
     'StyleSetHandleInlines.h',
     'StyleSheet.h',
     'StyleSheetInfo.h',
     'StyleSheetInlines.h',