[CI] Add LayoutSVGBlock::GetElement helper

Like the equivalent helper on LayoutSVGModelObject, this provides a more
specific type of Node (an SVGElement), since is guaranteed for
subclasses of LayoutSVGBlock.
Also update the documentation in LayoutSVGModelObject to reflect the
current name.

Bug: 769774
Change-Id: I720af53e5a24e960773059f7d2a113e74bd5bdc5
Reviewed-on: https://chromium-review.googlesource.com/973378
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Reviewed-by: Stephen Chenney <schenney@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#545034}

third_party/WebKit/Source/core/layout/svg/LayoutSVGBlock.cpp

@@ -35,6 +35,10 @@ namespace blink {
 LayoutSVGBlock::LayoutSVGBlock(SVGElement* element)
     : LayoutBlockFlow(element) {}
 
+SVGElement* LayoutSVGBlock::GetElement() const {
+  return ToSVGElement(LayoutObject::GetNode());
+}
+
 void LayoutSVGBlock::AbsoluteRects(Vector<IntRect>&, const LayoutPoint&) const {
   // This code path should never be taken for SVG, as we're assuming
   // useTransforms=true everywhere, absoluteQuads should be used.

third_party/WebKit/Source/core/layout/svg/LayoutSVGBlock.h

@@ -55,6 +55,8 @@ class LayoutSVGBlock : public LayoutBlockFlow {
 
   PaintLayerType LayerTypeRequired() const override { return kNoPaintLayer; }
 
+  SVGElement* GetElement() const;
+
  protected:
   void WillBeDestroyed() override;
   bool MapToVisualRectInAncestorSpaceInternal(
@@ -71,6 +73,9 @@ class LayoutSVGBlock : public LayoutBlockFlow {
   void StyleDidChange(StyleDifference, const ComputedStyle* old_style) override;
 
  private:
+  // LayoutSVGBlock subclasses should use GetElement() instead.
+  void GetNode() const = delete;
+
   LayoutRect AbsoluteVisualRect() const final;
 
   void AbsoluteRects(Vector<IntRect>&,

third_party/WebKit/Source/core/layout/svg/LayoutSVGForeignObject.cpp

@@ -48,26 +48,26 @@ void LayoutSVGForeignObject::Paint(const PaintInfo& paint_info,
 
 LayoutUnit LayoutSVGForeignObject::ElementX() const {
   return LayoutUnit(
-      roundf(SVGLengthContext(ToSVGElement(GetNode()))
+      roundf(SVGLengthContext(GetElement())
                  .ValueForLength(StyleRef().SvgStyle().X(), StyleRef(),
                                  SVGLengthMode::kWidth)));
 }
 
 LayoutUnit LayoutSVGForeignObject::ElementY() const {
   return LayoutUnit(
-      roundf(SVGLengthContext(ToSVGElement(GetNode()))
+      roundf(SVGLengthContext(GetElement())
                  .ValueForLength(StyleRef().SvgStyle().Y(), StyleRef(),
                                  SVGLengthMode::kHeight)));
 }
 
 LayoutUnit LayoutSVGForeignObject::ElementWidth() const {
-  return LayoutUnit(SVGLengthContext(ToSVGElement(GetNode()))
+  return LayoutUnit(SVGLengthContext(GetElement())
                         .ValueForLength(StyleRef().Width(), StyleRef(),
                                         SVGLengthMode::kWidth));
 }
 
 LayoutUnit LayoutSVGForeignObject::ElementHeight() const {
-  return LayoutUnit(SVGLengthContext(ToSVGElement(GetNode()))
+  return LayoutUnit(SVGLengthContext(GetElement())
                         .ValueForLength(StyleRef().Height(), StyleRef(),
                                         SVGLengthMode::kHeight));
 }
@@ -89,7 +89,7 @@ void LayoutSVGForeignObject::ComputeLogicalHeight(
 void LayoutSVGForeignObject::UpdateLayout() {
   DCHECK(NeedsLayout());
 
-  SVGForeignObjectElement* foreign = ToSVGForeignObjectElement(GetNode());
+  SVGForeignObjectElement* foreign = ToSVGForeignObjectElement(GetElement());
 
   bool update_cached_boundaries_in_parents = false;
   if (needs_transform_update_) {

third_party/WebKit/Source/core/layout/svg/LayoutSVGModelObject.h

@@ -92,7 +92,7 @@ class LayoutSVGModelObject : public LayoutObject {
   void WillBeDestroyed() override;
 
  private:
-  // LayoutSVGModelObject subclasses should use element() instead.
+  // LayoutSVGModelObject subclasses should use GetElement() instead.
   void GetNode() const = delete;
 
   // This method should never be called, SVG uses a different nodeAtPoint method

third_party/WebKit/Source/core/layout/svg/LayoutSVGText.cpp

@@ -202,8 +202,8 @@ void LayoutSVGText::UpdateLayout() {
     // the bounding box below, and after that we clear the
     // |needs_transform_update_| flag.
     if (needs_transform_update_) {
-      local_transform_ = ToSVGTextElement(GetNode())->CalculateTransform(
-          SVGElement::kIncludeMotionTransform);
+      local_transform_ =
+          GetElement()->CalculateTransform(SVGElement::kIncludeMotionTransform);
     }
 
     UpdateFontAndMetrics(*this);
@@ -267,8 +267,8 @@ void LayoutSVGText::UpdateLayout() {
   // changed too, since the transform could depend on the bounding
   // box.
   if (bounds_changed || needs_transform_update_) {
-    local_transform_ = ToSVGTextElement(GetNode())->CalculateTransform(
-        SVGElement::kIncludeMotionTransform);
+    local_transform_ =
+        GetElement()->CalculateTransform(SVGElement::kIncludeMotionTransform);
     needs_transform_update_ = false;
     update_parent_boundaries = true;
   }
@@ -331,7 +331,7 @@ bool LayoutSVGText::NodeAtFloatPoint(HitTestResult& result,
         const LayoutPoint& local_layout_point = LayoutPoint(local_point);
         UpdateHitTestResult(result, local_layout_point);
         if (result.AddNodeToListBasedTestResult(
-                GetNode(), local_layout_point) == kStopHitTesting)
+                GetElement(), local_layout_point) == kStopHitTesting)
           return true;
       }
     }
@@ -386,9 +386,8 @@ FloatRect LayoutSVGText::StrokeBoundingBox() const {
   if (!svg_style.HasStroke())
     return stroke_boundaries;
 
-  DCHECK(GetNode());
-  DCHECK(GetNode()->IsSVGElement());
-  SVGLengthContext length_context(ToSVGElement(GetNode()));
+  DCHECK(GetElement());
+  SVGLengthContext length_context(GetElement());
   stroke_boundaries.Inflate(
       length_context.ValueForLength(svg_style.StrokeWidth()));
   return stroke_boundaries;