Issue #1885 - Allow unitless rootMargin entries for IntersectionObserver.

I could have done this through a CSSLoader to allow all CSS unit quirks but
I wasn't planning to start passing around document and element references
everywhere, so instead just did it manually by accepting numbers/floats in
addition to pixel and percent.

1 files changed, 5 insertions, 1 deletions

diff --git a/dom/base/DOMIntersectionObserver.cpp b/dom/base/DOMIntersectionObserver.cpp
index bc8f030d0f..fb6315cc42 100644
--- a/dom/base/DOMIntersectionObserver.cpp
+++ b/dom/base/DOMIntersectionObserver.cpp
@@ -126,7 +126,9 @@ DOMIntersectionObserver::SetRootMargin(const nsAString& aString)
 
   for (uint32_t i = 0; i < ArrayLength(nsCSSRect::sides); ++i) {
     nsCSSValue value = mRootMargin.*nsCSSRect::sides[i];
-    if (!(value.IsPixelLengthUnit() || value.IsPercentLengthUnit())) {
+    if (!(value.IsPixelLengthUnit() ||
+          value.IsPercentLengthUnit() ||
+          value.IsFloatUnit(value.GetUnit()))) {
       return false;
     }
   }
@@ -327,6 +329,8 @@ DOMIntersectionObserver::Update(nsIDocument* aDocument, DOMHighResTimeStamp time
     nsStyleCoord coord;
     if (value.IsPixelLengthUnit()) {
       coord.SetCoordValue(value.GetPixelLength());
+    } else if (value.IsFloatUnit(value.GetUnit())) {
+      coord.SetCoordValue(value.GetFloatValue());
     } else if (value.IsPercentLengthUnit()) {
       coord.SetPercentValue(value.GetPercentValue());
     } else {