[CI] Add SVGLengthContext::ResolveLengthPair helper

With geometric presentation attributes it's quite common to need to
resolve an <x, y> pair of Lengths to produce a point or a size.
Add a helper ResolveLengthPair() that accepts a pair of Lengths and
return a FloatPoint. Except for a reduction in LoC, it also amortizes
the cost of determining a viewport when percentages are used.

Use the new helper for 'cx' / 'cy' and 'rx' / 'ry' on <ellipse>,
'cx' / 'cy' on <circle>, 'x' / 'y', 'width' / 'height' and 'rx' / 'ry'
on <rect>, 'x' / 'y' and 'width' / 'height' on <image> as well as
'x' / 'y' on <use>.

Since this means using FloatPoint/FloatSize to a larger degree than
before, use the abilities (operators et.c) of these a bit more where
possible.

Bug: 400725
Cq-Include-Trybots: master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: I15f5c17190b060a7e8312d5e3e124846301804b9
Reviewed-on: https://chromium-review.googlesource.com/832606Reviewed-by: Stephen Chenney <schenney@chromium.org>
Commit-Queue: Fredrik Söderquist <fs@opera.com>
Cr-Commit-Position: refs/heads/master@{#524740}

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

@@ -73,9 +73,7 @@ void LayoutSVGEllipse::UpdateShapeFromElement() {
   if (!use_path_fallback_)
     ClearPath();
 
-  fill_bounding_box_ =
-      FloatRect(center_.X() - radii_.Width(), center_.Y() - radii_.Height(),
-                2 * radii_.Width(), 2 * radii_.Height());
+  fill_bounding_box_ = FloatRect(center_ - radii_, radii_.ScaledBy(2));
   stroke_bounding_box_ = fill_bounding_box_;
   if (Style()->SvgStyle().HasStroke())
     stroke_bounding_box_.Inflate(StrokeWidth() / 2);
@@ -84,22 +82,18 @@ void LayoutSVGEllipse::UpdateShapeFromElement() {
 void LayoutSVGEllipse::CalculateRadiiAndCenter() {
   DCHECK(GetElement());
   SVGLengthContext length_context(GetElement());
-  center_ = FloatPoint(
-      length_context.ValueForLength(Style()->SvgStyle().Cx(), StyleRef(),
-                                    SVGLengthMode::kWidth),
-      length_context.ValueForLength(Style()->SvgStyle().Cy(), StyleRef(),
-                                    SVGLengthMode::kHeight));
+  const ComputedStyle& style = StyleRef();
+  const SVGComputedStyle& svg_style = style.SvgStyle();
+  center_ =
+      length_context.ResolveLengthPair(svg_style.Cx(), svg_style.Cy(), style);
 
   if (IsSVGCircleElement(*GetElement())) {
-    float radius = length_context.ValueForLength(
-        Style()->SvgStyle().R(), StyleRef(), SVGLengthMode::kOther);
+    float radius = length_context.ValueForLength(svg_style.R(), style,
+                                                 SVGLengthMode::kOther);
     radii_ = FloatSize(radius, radius);
   } else {
-    radii_ = FloatSize(
-        length_context.ValueForLength(Style()->SvgStyle().Rx(), StyleRef(),
-                                      SVGLengthMode::kWidth),
-        length_context.ValueForLength(Style()->SvgStyle().Ry(), StyleRef(),
-                                      SVGLengthMode::kHeight));
+    radii_ = ToFloatSize(length_context.ResolveLengthPair(
+        svg_style.Rx(), svg_style.Ry(), style));
   }
 }
 

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

@@ -90,17 +90,14 @@ bool LayoutSVGImage::UpdateBoundingBox() {
   FloatRect old_object_bounding_box = object_bounding_box_;
 
   SVGLengthContext length_context(GetElement());
+  const ComputedStyle& style = StyleRef();
+  const SVGComputedStyle& svg_style = style.SvgStyle();
   object_bounding_box_ = FloatRect(
-      length_context.ValueForLength(StyleRef().SvgStyle().X(), StyleRef(),
-                                    SVGLengthMode::kWidth),
-      length_context.ValueForLength(StyleRef().SvgStyle().Y(), StyleRef(),
-                                    SVGLengthMode::kHeight),
-      length_context.ValueForLength(StyleRef().Width(), StyleRef(),
-                                    SVGLengthMode::kWidth),
-      length_context.ValueForLength(StyleRef().Height(), StyleRef(),
-                                    SVGLengthMode::kHeight));
-
-  if (StyleRef().Width().IsAuto() || StyleRef().Height().IsAuto())
+      length_context.ResolveLengthPair(svg_style.X(), svg_style.Y(), style),
+      ToFloatSize(length_context.ResolveLengthPair(style.Width(),
+                                                   style.Height(), style)));
+
+  if (style.Width().IsAuto() || style.Height().IsAuto())
     object_bounding_box_.SetSize(CalculateObjectSize());
 
   if (old_object_bounding_box != object_bounding_box_) {

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

@@ -47,16 +47,15 @@ void LayoutSVGRect::UpdateShapeFromElement() {
   DCHECK(rect);
 
   SVGLengthContext length_context(rect);
-  FloatSize bounding_box_size(
-      length_context.ValueForLength(StyleRef().Width(), StyleRef(),
-                                    SVGLengthMode::kWidth),
-      length_context.ValueForLength(StyleRef().Height(), StyleRef(),
-                                    SVGLengthMode::kHeight));
+  const ComputedStyle& style = StyleRef();
+  FloatSize bounding_box_size(ToFloatSize(
+      length_context.ResolveLengthPair(style.Width(), style.Height(), style)));
 
   // Spec: "A negative value is an error."
   if (bounding_box_size.Width() < 0 || bounding_box_size.Height() < 0)
     return;
 
+  const SVGComputedStyle& svg_style = style.SvgStyle();
   // Spec: "A value of zero disables rendering of the element."
   if (!bounding_box_size.IsEmpty()) {
     // Fallback to LayoutSVGShape and path-based hit detection if the rect
@@ -69,25 +68,19 @@ void LayoutSVGRect::UpdateShapeFromElement() {
       use_path_fallback_ = true;
       return;
     }
-    if (length_context.ValueForLength(StyleRef().SvgStyle().Rx(), StyleRef(),
-                                      SVGLengthMode::kWidth) > 0 ||
-        length_context.ValueForLength(StyleRef().SvgStyle().Ry(), StyleRef(),
-                                      SVGLengthMode::kHeight) > 0 ||
-        !DefinitelyHasSimpleStroke()) {
+    FloatPoint radii(length_context.ResolveLengthPair(svg_style.Rx(),
+                                                      svg_style.Ry(), style));
+    if (radii.X() > 0 || radii.Y() > 0 || !DefinitelyHasSimpleStroke()) {
       CreatePath();
       use_path_fallback_ = true;
     }
   }
 
   fill_bounding_box_ = FloatRect(
-      FloatPoint(
-          length_context.ValueForLength(StyleRef().SvgStyle().X(), StyleRef(),
-                                        SVGLengthMode::kWidth),
-          length_context.ValueForLength(StyleRef().SvgStyle().Y(), StyleRef(),
-                                        SVGLengthMode::kHeight)),
+      length_context.ResolveLengthPair(svg_style.X(), svg_style.Y(), style),
       bounding_box_size);
   stroke_bounding_box_ = fill_bounding_box_;
-  if (Style()->SvgStyle().HasStroke())
+  if (svg_style.HasStroke())
     stroke_bounding_box_.Inflate(StrokeWidth() / 2);
 }
 

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

@@ -95,10 +95,8 @@ SVGTransformChange LayoutSVGTransformableContainer::CalculateLocalTransform() {
     const ComputedStyle& style = StyleRef();
     const SVGComputedStyle& svg_style = style.SvgStyle();
     SVGLengthContext length_context(element);
-    FloatSize translation(length_context.ValueForLength(svg_style.X(), style,
-                                                        SVGLengthMode::kWidth),
-                          length_context.ValueForLength(
-                              svg_style.Y(), style, SVGLengthMode::kHeight));
+    FloatSize translation(ToFloatSize(
+        length_context.ResolveLengthPair(svg_style.X(), svg_style.Y(), style)));
     // TODO(fs): Signal this on style update instead.
     if (translation != additional_translation_)
       SetNeedsTransformUpdate();

third_party/WebKit/Source/core/svg/SVGCircleElement.cpp

@@ -65,16 +65,11 @@ Path SVGCircleElement::AsPath() const {
   float r = length_context.ValueForLength(svg_style.R(), style,
                                           SVGLengthMode::kOther);
   if (r > 0) {
-    path.AddEllipse(
-        FloatRect(length_context.ValueForLength(svg_style.Cx(), style,
-                                                SVGLengthMode::kWidth) -
-                      r,
-                  length_context.ValueForLength(svg_style.Cy(), style,
-                                                SVGLengthMode::kHeight) -
-                      r,
-                  r * 2, r * 2));
+    FloatPoint center(length_context.ResolveLengthPair(svg_style.Cx(),
+                                                       svg_style.Cy(), style));
+    FloatSize radii(r, r);
+    path.AddEllipse(FloatRect(center - radii, radii.ScaledBy(2)));
   }
-
   return path;
 }
 

third_party/WebKit/Source/core/svg/SVGEllipseElement.cpp

@@ -68,25 +68,15 @@ Path SVGEllipseElement::AsPath() const {
   const ComputedStyle& style = GetLayoutObject()->StyleRef();
   const SVGComputedStyle& svg_style = style.SvgStyle();
 
-  float rx = length_context.ValueForLength(svg_style.Rx(), style,
-                                           SVGLengthMode::kWidth);
-  if (rx < 0)
+  FloatSize radii(ToFloatSize(
+      length_context.ResolveLengthPair(svg_style.Rx(), svg_style.Ry(), style)));
+  if (radii.Width() < 0 || radii.Height() < 0 ||
+      (!radii.Width() && !radii.Height()))
     return path;
-  float ry = length_context.ValueForLength(svg_style.Ry(), style,
-                                           SVGLengthMode::kHeight);
-  if (ry < 0)
-    return path;
-  if (!rx && !ry)
-    return path;
-
-  path.AddEllipse(FloatRect(length_context.ValueForLength(
-                                svg_style.Cx(), style, SVGLengthMode::kWidth) -
-                                rx,
-                            length_context.ValueForLength(
-                                svg_style.Cy(), style, SVGLengthMode::kHeight) -
-                                ry,
-                            rx * 2, ry * 2));
 
+  FloatPoint center(
+      length_context.ResolveLengthPair(svg_style.Cx(), svg_style.Cy(), style));
+  path.AddEllipse(FloatRect(center - radii, radii.ScaledBy(2)));
   return path;
 }
 

third_party/WebKit/Source/core/svg/SVGLengthContext.cpp

@@ -197,6 +197,19 @@ FloatPoint SVGLengthContext::ResolvePoint(const SVGElement* context,
   return FloatPoint(x.ValueAsPercentage(), y.ValueAsPercentage());
 }
 
+FloatPoint SVGLengthContext::ResolveLengthPair(
+    const Length& x_length,
+    const Length& y_length,
+    const ComputedStyle& style) const {
+  FloatSize viewport_size;
+  if (x_length.IsPercentOrCalc() || y_length.IsPercentOrCalc())
+    DetermineViewport(viewport_size);
+
+  float zoom = style.EffectiveZoom();
+  return FloatPoint(ValueForLength(x_length, zoom, viewport_size.Width()),
+                    ValueForLength(y_length, zoom, viewport_size.Height()));
+}
+
 float SVGLengthContext::ResolveLength(const SVGElement* context,
                                       SVGUnitTypes::SVGUnitType type,
                                       const SVGLength& x) {

third_party/WebKit/Source/core/svg/SVGLengthContext.h

@@ -64,6 +64,9 @@ class SVGLengthContext {
   static float ResolveLength(const SVGElement*,
                              SVGUnitTypes::SVGUnitType,
                              const SVGLength&);
+  FloatPoint ResolveLengthPair(const Length& x_length,
+                               const Length& y_length,
+                               const ComputedStyle&) const;
 
   float ConvertValueToUserUnits(float,
                                 SVGLengthMode,

third_party/WebKit/Source/core/svg/SVGRectElement.cpp

@@ -79,40 +79,29 @@ Path SVGRectElement::AsPath() const {
   SVGLengthContext length_context(this);
   DCHECK(GetLayoutObject());
   const ComputedStyle& style = GetLayoutObject()->StyleRef();
-  const SVGComputedStyle& svg_style = style.SvgStyle();
 
-  float width = length_context.ValueForLength(style.Width(), style,
-                                              SVGLengthMode::kWidth);
-  if (width < 0)
-    return path;
-  float height = length_context.ValueForLength(style.Height(), style,
-                                               SVGLengthMode::kHeight);
-  if (height < 0)
-    return path;
-  if (!width && !height)
+  FloatSize size(ToFloatSize(
+      length_context.ResolveLengthPair(style.Width(), style.Height(), style)));
+  if (size.Width() < 0 || size.Height() < 0 ||
+      (!size.Width() && !size.Height()))
     return path;
 
-  float x = length_context.ValueForLength(svg_style.X(), style,
-                                          SVGLengthMode::kWidth);
-  float y = length_context.ValueForLength(svg_style.Y(), style,
-                                          SVGLengthMode::kHeight);
-  float rx = length_context.ValueForLength(svg_style.Rx(), style,
-                                           SVGLengthMode::kWidth);
-  float ry = length_context.ValueForLength(svg_style.Ry(), style,
-                                           SVGLengthMode::kHeight);
-  bool has_rx = rx > 0;
-  bool has_ry = ry > 0;
-  if (has_rx || has_ry) {
+  const SVGComputedStyle& svg_style = style.SvgStyle();
+  FloatRect rect(
+      length_context.ResolveLengthPair(svg_style.X(), svg_style.Y(), style),
+      size);
+  FloatPoint radii(
+      length_context.ResolveLengthPair(svg_style.Rx(), svg_style.Ry(), style));
+  if (radii.X() > 0 || radii.Y() > 0) {
     if (svg_style.Rx().IsAuto())
-      rx = ry;
+      radii.SetX(radii.Y());
     else if (svg_style.Ry().IsAuto())
-      ry = rx;
+      radii.SetY(radii.X());
 
-    path.AddRoundedRect(FloatRect(x, y, width, height), FloatSize(rx, ry));
-    return path;
+    path.AddRoundedRect(rect, ToFloatSize(radii));
+  } else {
+    path.AddRect(rect);
   }
-
-  path.AddRect(FloatRect(x, y, width, height));
   return path;
 }