Bug 1285235 - Add EnsureLengthAtLeast function to nsStyleImageLayers for Stylo; r=bholley

layout/style/ServoBindings.cpp

@@ -567,6 +567,15 @@ Gecko_EnsureTArrayCapacity(void* aArray, size_t aCapacity, size_t aElemSize) {
   base->EnsureCapacity<nsTArrayInfallibleAllocator>(aCapacity, aElemSize);
 }
 
+void Gecko_EnsureImageLayersLength(nsStyleImageLayers* aLayers, size_t aLen) {
+  aLayers->mLayers.EnsureLengthAtLeast(aLen);
+}
+
+void Gecko_InitializeImageLayer(nsStyleImageLayers_Layer* aLayer, uint8_t aLayerType) {
+  auto layer = reinterpret_cast<nsStyleImageLayers::Layer*>(aLayer);
+  layer->Initialize(static_cast<nsStyleImageLayers::LayerType>(aLayerType));
+}
+
 #define STYLE_STRUCT(name, checkdata_cb)                                      \
                                                                               \
 void                                                                          \

layout/style/ServoBindings.h

@@ -44,6 +44,8 @@ struct RawServoStyleSet;
 class nsHTMLCSSStyleSheet;
 struct nsStyleList;
 struct nsStyleImage;
+struct nsStyleImageLayers;
+struct nsStyleImageLayers_Layer;
 struct nsStyleGradientStop;
 class nsStyleGradient;
 class nsStyleCoord;
@@ -186,6 +188,11 @@ void Gecko_UnsetNodeFlags(RawGeckoNode* node, uint32_t flags);
 // friend function declaration in nsTArray.h
 void Gecko_EnsureTArrayCapacity(void* array, size_t capacity, size_t elem_size);
 
+
+void Gecko_EnsureImageLayersLength(nsStyleImageLayers* layers, size_t len);
+
+// fill_type is a nsStyleImageLayers::LayerType
+void Gecko_InitializeImageLayer(nsStyleImageLayers_Layer* layer, uint8_t layer_type);
 // Styleset and Stylesheet management.
 //
 // TODO: Make these return already_AddRefed and UniquePtr when the binding