1 files changed, 47 insertions, 0 deletions
diff --git a/docshell/base/timeline/LayerTimelineMarker.h b/docshell/base/timeline/LayerTimelineMarker.h
new file mode 100644
index 0000000000..7c7336ba52
--- /dev/null
+++ b/docshell/base/timeline/LayerTimelineMarker.h
@@ -0,0 +1,47 @@
+/* -*- 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_LayerTimelineMarker_h_
+#define mozilla_LayerTimelineMarker_h_
+
+#include "TimelineMarker.h"
+#include "mozilla/dom/ProfileTimelineMarkerBinding.h"
+#include "mozilla/mozalloc_oom.h"
+#include "nsRegion.h"
+
+namespace mozilla {
+
+class LayerTimelineMarker : public TimelineMarker {
+ public:
+  explicit LayerTimelineMarker(const nsIntRegion& aRegion)
+      : TimelineMarker("Layer", MarkerTracingType::HELPER_EVENT),
+        mRegion(aRegion) {}
+
+  void AddLayerRectangles(
+      dom::Sequence<dom::ProfileTimelineLayerRect>& aRectangles) {
+    for (auto iter = mRegion.RectIter(); !iter.Done(); iter.Next()) {
+      const nsIntRect& iterRect = iter.Get();
+      dom::ProfileTimelineLayerRect rect;
+      rect.mX = iterRect.X();
+      rect.mY = iterRect.Y();
+      rect.mWidth = iterRect.Width();
+      rect.mHeight = iterRect.Height();
+      if (!aRectangles.AppendElement(rect, fallible)) {
+        // XXX(Bug 1632090) Instead of extending the array 1-by-1 (which might
+        // involve multiple reallocations) and potentially crashing here,
+        // SetCapacity could be called outside the loop once.
+        mozalloc_handle_oom(0);
+      }
+    }
+  }
+
+ private:
+  nsIntRegion mRegion;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_LayerTimelineMarker_h_