Decouple content transform fiddling from SVGRenderingContext::renderSubtree

Source/core/rendering/svg/SVGRenderingContext.h

Index: Source/core/rendering/svg/SVGRenderingContext.h
diff --git a/Source/core/rendering/svg/SVGRenderingContext.h b/Source/core/rendering/svg/SVGRenderingContext.h
index 9e9cb82c530401d1ec2bc9ae76fdf5caac168c4b..714bff3f3896ab9a857b4e5985c00d0ddd85dfa6 100644
--- a/Source/core/rendering/svg/SVGRenderingContext.h
+++ b/Source/core/rendering/svg/SVGRenderingContext.h
@@ -28,15 +28,24 @@
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/svg/RenderSVGResourceClipper.h"
 #include "platform/graphics/ImageBuffer.h"
+#include "platform/transforms/AffineTransform.h"
 
 namespace blink {
 
-class AffineTransform;
 class RenderObject;
 class FloatRect;
 class RenderSVGResourceFilter;
 class RenderSVGResourceMasker;
 
+class SubtreeContentTransformScope {
+public:
+    SubtreeContentTransformScope(const AffineTransform&);
+    ~SubtreeContentTransformScope();
+
+private:
+    AffineTransform m_savedContentTransformation;
+};
+
 // SVGRenderingContext
 class SVGRenderingContext {
 public:
@@ -73,7 +82,7 @@ public:
     void prepareToRenderSVGContent(RenderObject*, PaintInfo&);
     bool isRenderingPrepared() const { return m_renderingFlags & RenderingPrepared; }
 
-    static void renderSubtree(GraphicsContext*, RenderObject*, const AffineTransform&);
+    static void renderSubtree(GraphicsContext*, RenderObject*);
 
     static float calculateScreenFontSizeScalingFactor(const RenderObject*);
     static void calculateDeviceSpaceTransformation(const RenderObject*, AffineTransform& absoluteTransform);