--- a/gfx/layers/wr/WebRenderUserData.cpp
+++ b/gfx/layers/wr/WebRenderUserData.cpp
@@ -164,10 +164,16 @@ WebRenderFallbackData::GetGeometry()
 }
 
 void
 WebRenderFallbackData::SetGeometry(nsAutoPtr<nsDisplayItemGeometry> aGeometry)
 {
   mGeometry = aGeometry;
 }
 
+WebRenderAnimationData::WebRenderAnimationData(WebRenderLayerManager* aWRManager)
+  : WebRenderUserData(aWRManager),
+    mAnimationInfo(aWRManager)
+{
+}
+
 } // namespace layers
 } // namespace mozilla

--- a/gfx/layers/wr/WebRenderUserData.h
+++ b/gfx/layers/wr/WebRenderUserData.h
@@ -3,16 +3,17 @@
  * 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 GFX_WEBRENDERUSERDATA_H
 #define GFX_WEBRENDERUSERDATA_H
 
 #include "mozilla/layers/StackingContextHelper.h"
 #include "mozilla/webrender/WebRenderAPI.h"
+#include "mozilla/layers/AnimationInfo.h"
 
 class nsDisplayItemGeometry;
 
 namespace mozilla {
 namespace layers {
 class ImageClient;
 class ImageContainer;
 class WebRenderBridgeChild;
@@ -28,16 +29,17 @@ public:
     : mWRManager(aWRManager)
   { }
 
   virtual WebRenderImageData* AsImageData() { return nullptr; }
 
   enum class UserDataType {
     eImage,
     eFallback,
+    eAnimation,
   };
 
   virtual UserDataType GetType() = 0;
 
 protected:
   virtual ~WebRenderUserData() {}
 
   WebRenderBridgeChild* WrBridge() const;
@@ -95,12 +97,26 @@ public:
   nsRect GetBounds() { return mBounds; }
   void SetBounds(const nsRect& aRect) { mBounds = aRect; }
 
 protected:
   nsAutoPtr<nsDisplayItemGeometry> mGeometry;
   nsRect mBounds;
 };
 
+class WebRenderAnimationData : public WebRenderUserData
+{
+public:
+  explicit WebRenderAnimationData(WebRenderLayerManager* aWRManager);
+  virtual ~WebRenderAnimationData() {}
+
+  virtual UserDataType GetType() override { return UserDataType::eAnimation; }
+  static UserDataType Type() { return UserDataType::eAnimation; }
+  AnimationInfo& GetAnimationInfo() { return mAnimationInfo; }
+
+protected:
+  AnimationInfo mAnimationInfo;
+};
+
 } // namespace layers
 } // namespace mozilla
 
 #endif /* GFX_WEBRENDERUSERDATA_H */

--- a/layout/painting/nsDisplayList.cpp
+++ b/layout/painting/nsDisplayList.cpp
@@ -6054,26 +6054,45 @@ nsDisplayOpacity::CreateWebRenderCommand
 {
   nsRect itemBounds = mList.GetClippedBoundsWithRespectToASR(aDisplayListBuilder, mActiveScrolledRoot);
   nsRect childrenVisible = GetVisibleRectForChildren();
   nsRect visibleRect = itemBounds.Intersect(childrenVisible);
   float appUnitsPerDevPixel = mFrame->PresContext()->AppUnitsPerDevPixel();
   LayerRect bounds = ViewAs<LayerPixel>(LayoutDeviceRect::FromAppUnits(visibleRect, appUnitsPerDevPixel),
                                         PixelCastJustification::WebRenderHasUnitResolution);
   LayerPoint origin = bounds.TopLeft();
-
-  // TODO: generate animationsId for OMTA.
+  float* opacityForSC = &mOpacity;
+
+  RefPtr<WebRenderAnimationData> animationData = aManager->CreateOrRecycleWebRenderUserData<WebRenderAnimationData>(this);
+  AnimationInfo& animationInfo = animationData->GetAnimationInfo();
+  AddAnimationsForProperty(Frame(), aDisplayListBuilder,
+                           this, eCSSProperty_opacity,
+                           animationInfo, false);
+  animationInfo.StartPendingAnimations(aManager->GetAnimationReadyTime());
   uint64_t animationsId = 0;
+
+  if (gfxPrefs::WebRenderOMTAEnabled() &&
+      !animationInfo.GetAnimations().IsEmpty()) {
+    animationsId = animationInfo.GetCompositorAnimationsId();
+    opacityForSC = nullptr;
+    OptionalOpacity opacityForCompositor = mOpacity;
+
+    OpAddCompositorAnimations
+      anim(CompositorAnimations(animationInfo.GetAnimations(), animationsId),
+           void_t(), opacityForCompositor);
+    aManager->WrBridge()->AddWebRenderParentCommand(anim);
+  }
+
   nsTArray<WrFilterOp> filters;
   StackingContextHelper sc(aSc,
                            aBuilder,
                            bounds,
                            origin,
                            animationsId,
-                           &mOpacity,
+                           opacityForSC,
                            nullptr,
                            filters);
 
   aManager->CreateWebRenderCommandsFromDisplayList(&mList,
                                                    aDisplayListBuilder,
                                                    sc,
                                                    aBuilder);
   return true;
@@ -7604,18 +7623,44 @@ nsDisplayTransform::CreateWebRenderComma
   boundTransform._41 = 0.0f;
   boundTransform._42 = 0.0f;
   boundTransform._43 = 0.0f;
   if (!boundTransform.IsIdentity()) {
     // WR will only apply the 'translate' of the transform, so we need to do the scale/rotation manually.
     bounds.MoveTo(boundTransform.TransformPoint(bounds.TopLeft()));
   }
 
-  // TODO: generate animationsId for OMTA.
+  RefPtr<WebRenderAnimationData> animationData = aManager->CreateOrRecycleWebRenderUserData<WebRenderAnimationData>(this);
+
+  AnimationInfo& animationInfo = animationData->GetAnimationInfo();
+  AddAnimationsForProperty(Frame(), aDisplayListBuilder,
+                           this, eCSSProperty_transform,
+                           animationInfo, false);
+  animationInfo.StartPendingAnimations(aManager->GetAnimationReadyTime());
   uint64_t animationsId = 0;
+
+  if (gfxPrefs::WebRenderOMTAEnabled() &&
+      !animationInfo.GetAnimations().IsEmpty()) {
+    animationsId = animationInfo.GetCompositorAnimationsId();
+
+    // Update transfrom as nullptr in stacking context if there exists
+    // transform animation, the transform value will be resolved
+    // after animation sampling on the compositor
+    transformForSC = nullptr;
+
+    // Pass default transform to compositor in case gecko fails to
+    // get animated value after animation sampling.
+    OptionalTransform transformForCompositor = newTransformMatrix;
+
+    OpAddCompositorAnimations
+      anim(CompositorAnimations(animationInfo.GetAnimations(), animationsId),
+           transformForCompositor, void_t());
+    aManager->WrBridge()->AddWebRenderParentCommand(anim);
+  }
+
   nsTArray<WrFilterOp> filters;
   StackingContextHelper sc(aSc,
                            aBuilder,
                            bounds,
                            origin,
                            animationsId,
                            nullptr,
                            transformForSC,