diff -r 000000000000 -r 6474c204b198 layout/svg/SVGViewFrame.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/layout/svg/SVGViewFrame.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,130 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+// Keep in (case-insensitive) order:
+#include "nsFrame.h"
+#include "nsGkAtoms.h"
+#include "nsSVGOuterSVGFrame.h"
+#include "mozilla/dom/SVGSVGElement.h"
+#include "mozilla/dom/SVGViewElement.h"
+
+typedef nsFrame SVGViewFrameBase;
+
+using namespace mozilla::dom;
+
+/**
+ * While views are not directly rendered in SVG they can be linked to
+ * and thereby override attributes of an <svg> element via a fragment
+ * identifier. The SVGViewFrame class passes on any attribute changes
+ * the view receives to the overridden <svg> element (if there is one).
+ **/
+class SVGViewFrame : public SVGViewFrameBase
+{
+  friend nsIFrame*
+  NS_NewSVGViewFrame(nsIPresShell* aPresShell, nsStyleContext* aContext);
+protected:
+  SVGViewFrame(nsStyleContext* aContext)
+    : SVGViewFrameBase(aContext)
+  {
+    AddStateBits(NS_FRAME_IS_NONDISPLAY);
+  }
+
+public:
+  NS_DECL_FRAMEARENA_HELPERS
+
+#ifdef DEBUG
+  virtual void Init(nsIContent* aContent,
+                    nsIFrame*   aParent,
+                    nsIFrame*   aPrevInFlow) MOZ_OVERRIDE;
+#endif
+
+  virtual bool IsFrameOfType(uint32_t aFlags) const MOZ_OVERRIDE
+  {
+    return SVGViewFrameBase::IsFrameOfType(aFlags & ~(nsIFrame::eSVG));
+  }
+
+#ifdef DEBUG_FRAME_DUMP
+  virtual nsresult GetFrameName(nsAString& aResult) const MOZ_OVERRIDE
+  {
+    return MakeFrameName(NS_LITERAL_STRING("SVGView"), aResult);
+  }
+#endif
+
+  /**
+   * Get the "type" of the frame
+   *
+   * @see nsGkAtoms::svgFELeafFrame
+   */
+  virtual nsIAtom* GetType() const MOZ_OVERRIDE;
+
+  virtual nsresult AttributeChanged(int32_t  aNameSpaceID,
+                                    nsIAtom* aAttribute,
+                                    int32_t  aModType) MOZ_OVERRIDE;
+
+  virtual bool UpdateOverflow() MOZ_OVERRIDE {
+    // We don't maintain a visual overflow rect
+    return false;
+  }
+};
+
+nsIFrame*
+NS_NewSVGViewFrame(nsIPresShell* aPresShell, nsStyleContext* aContext)
+{
+  return new (aPresShell) SVGViewFrame(aContext);
+}
+
+NS_IMPL_FRAMEARENA_HELPERS(SVGViewFrame)
+
+#ifdef DEBUG
+void
+SVGViewFrame::Init(nsIContent* aContent,
+                   nsIFrame* aParent,
+                   nsIFrame* aPrevInFlow)
+{
+  NS_ASSERTION(aContent->IsSVG(nsGkAtoms::view),
+               "Content is not an SVG view");
+
+  SVGViewFrameBase::Init(aContent, aParent, aPrevInFlow);
+}
+#endif /* DEBUG */
+
+nsIAtom *
+SVGViewFrame::GetType() const
+{
+  return nsGkAtoms::svgViewFrame;
+}
+
+nsresult
+SVGViewFrame::AttributeChanged(int32_t  aNameSpaceID,
+                               nsIAtom* aAttribute,
+                               int32_t  aModType)
+{
+  // Ignore zoomAndPan as it does not cause the <svg> element to re-render
+    
+  if (aNameSpaceID == kNameSpaceID_None &&
+      (aAttribute == nsGkAtoms::preserveAspectRatio ||
+       aAttribute == nsGkAtoms::viewBox ||
+       aAttribute == nsGkAtoms::viewTarget)) {
+
+    nsSVGOuterSVGFrame *outerSVGFrame = nsSVGUtils::GetOuterSVGFrame(this);
+    NS_ASSERTION(outerSVGFrame->GetContent()->IsSVG(nsGkAtoms::svg),
+                 "Expecting an <svg> element");
+
+    SVGSVGElement* svgElement =
+      static_cast<SVGSVGElement*>(outerSVGFrame->GetContent());
+
+    nsAutoString viewID;
+    mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::id, viewID);
+
+    if (svgElement->IsOverriddenBy(viewID)) {
+      // We're the view that's providing overrides, so pretend that the frame
+      // we're overriding was updated.
+      outerSVGFrame->AttributeChanged(aNameSpaceID, aAttribute, aModType);
+    }
+  }
+
+  return SVGViewFrameBase::AttributeChanged(aNameSpaceID,
+                                            aAttribute, aModType);
+}