1 files changed, 53 insertions, 0 deletions
diff --git a/gfx/layers/apz/src/AsyncDragMetrics.h b/gfx/layers/apz/src/AsyncDragMetrics.h
new file mode 100644
index 0000000000..f7f24c3781
--- /dev/null
+++ b/gfx/layers/apz/src/AsyncDragMetrics.h
@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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_layers_DragMetrics_h
+#define mozilla_layers_DragMetrics_h
+
+#include "mozilla/layers/ScrollableLayerGuid.h"
+#include "LayersTypes.h"
+#include "mozilla/Maybe.h"
+
+namespace IPC {
+template <typename T>
+struct ParamTraits;
+}  // namespace IPC
+
+namespace mozilla {
+
+namespace layers {
+
+class AsyncDragMetrics {
+  friend struct IPC::ParamTraits<mozilla::layers::AsyncDragMetrics>;
+
+ public:
+  // IPC constructor
+  AsyncDragMetrics()
+      : mViewId(0),
+        mPresShellId(0),
+        mDragStartSequenceNumber(0),
+        mScrollbarDragOffset(0) {}
+
+  AsyncDragMetrics(const ScrollableLayerGuid::ViewID& aViewId,
+                   uint32_t aPresShellId, uint64_t aDragStartSequenceNumber,
+                   CSSCoord aScrollbarDragOffset, ScrollDirection aDirection)
+      : mViewId(aViewId),
+        mPresShellId(aPresShellId),
+        mDragStartSequenceNumber(aDragStartSequenceNumber),
+        mScrollbarDragOffset(aScrollbarDragOffset),
+        mDirection(Some(aDirection)) {}
+
+  ScrollableLayerGuid::ViewID mViewId;
+  uint32_t mPresShellId;
+  uint64_t mDragStartSequenceNumber;
+  CSSCoord mScrollbarDragOffset;  // relative to the thumb's start offset
+  Maybe<ScrollDirection> mDirection;
+};
+
+}  // namespace layers
+}  // namespace mozilla
+
+#endif