--- a/dom/canvas/CanvasRenderingContext2D.cpp
+++ b/dom/canvas/CanvasRenderingContext2D.cpp
@@ -899,19 +899,16 @@ public:
   static void PreTransactionCallback(void* aData)
   {
     CanvasRenderingContext2DUserData* self =
       static_cast<CanvasRenderingContext2DUserData*>(aData);
     CanvasRenderingContext2D* context = self->mContext;
     if (!context || !context->mTarget)
       return;
 
-    // Since SkiaGL default to store drawing command until flush
-    // We will have to flush it before present.
-    context->mTarget->Flush();
     context->ReturnTarget();
   }
 
   static void DidTransactionCallback(void* aData)
   {
     CanvasRenderingContext2DUserData* self =
       static_cast<CanvasRenderingContext2DUserData*>(aData);
     if (self->mContext) {

--- a/gfx/layers/PersistentBufferProvider.cpp
+++ b/gfx/layers/PersistentBufferProvider.cpp
@@ -35,16 +35,21 @@ PersistentBufferProviderBasic::BorrowDra
   return dt.forget();
 }
 
 bool
 PersistentBufferProviderBasic::ReturnDrawTarget(already_AddRefed<gfx::DrawTarget> aDT)
 {
   RefPtr<gfx::DrawTarget> dt(aDT);
   MOZ_ASSERT(mDrawTarget == dt);
+  if (dt) {
+    // Since SkiaGL default to storing drawing command until flush
+    // we have to flush it before present.
+    dt->Flush();
+  }
   return true;
 }
 
 already_AddRefed<gfx::SourceSurface>
 PersistentBufferProviderBasic::BorrowSnapshot()
 {
   mSnapshot = mDrawTarget->Snapshot();
   RefPtr<SourceSurface> snapshot = mSnapshot;