Move Color::SerializedAsCSSComponentValue to CSSColorValue.

This special serialization behavior belongs in the css directory. Also, in
a subsequent CL (for css-properties-values-api), it will be necessary to
expose the alpha rounding part of the serialization, and I don't want to
add this function to platform/color.h.

Change-Id: I4512e695016b6495c6b9197b521cda6431642962
Reviewed-on: https://chromium-review.googlesource.com/c/1293614Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Anders Ruud <andruud@chromium.org>
Cr-Commit-Position: refs/heads/master@{#602404}

third_party/blink/renderer/core/css/css_color_value.cc

@@ -5,6 +5,7 @@
 #include "third_party/blink/renderer/core/css/css_color_value.h"
 
 #include "third_party/blink/renderer/core/css/css_value_pool.h"
+#include "third_party/blink/renderer/platform/wtf/text/string_builder.h"
 
 namespace blink {
 namespace cssvalue {
@@ -26,5 +27,39 @@ CSSColorValue* CSSColorValue::Create(RGBA32 color) {
   return entry.stored_value->value;
 }
 
+String CSSColorValue::SerializeAsCSSComponentValue(Color color) {
+  StringBuilder result;
+  result.ReserveCapacity(32);
+  bool color_has_alpha = color.HasAlpha();
+  if (color_has_alpha)
+    result.Append("rgba(");
+  else
+    result.Append("rgb(");
+
+  result.AppendNumber(static_cast<unsigned char>(color.Red()));
+  result.Append(", ");
+
+  result.AppendNumber(static_cast<unsigned char>(color.Green()));
+  result.Append(", ");
+
+  result.AppendNumber(static_cast<unsigned char>(color.Blue()));
+  if (color_has_alpha) {
+    result.Append(", ");
+    // See <alphavalue> section in
+    // https://drafts.csswg.org/cssom/#serializing-css-values
+    int alphavalue = color.Alpha();
+    float rounded = round(alphavalue * 100 / 255.0f) / 100;
+    if (round(rounded * 255) == alphavalue) {
+      result.AppendNumber(rounded, 2);
+    } else {
+      rounded = round(alphavalue * 1000 / 255.0f) / 1000;
+      result.AppendNumber(rounded, 3);
+    }
+  }
+
+  result.Append(')');
+  return result.ToString();
+}
+
 }  // namespace cssvalue
 }  // namespace blink

third_party/blink/renderer/core/css/css_color_value.h

@@ -21,9 +21,7 @@ class CSSColorValue : public CSSValue {
   // TODO(sashab): Make this create() method take a Color instead.
   static CSSColorValue* Create(RGBA32 color);
 
-  String CustomCSSText() const {
-    return color_.SerializedAsCSSComponentValue();
-  }
+  String CustomCSSText() const { return SerializeAsCSSComponentValue(color_); }
 
   Color Value() const { return color_; }
 
@@ -35,6 +33,10 @@ class CSSColorValue : public CSSValue {
     CSSValue::TraceAfterDispatch(visitor);
   }
 
+  // Returns the color serialized according to CSSOM:
+  // https://drafts.csswg.org/cssom/#serialize-a-css-component-value
+  static String SerializeAsCSSComponentValue(Color color);
+
  private:
   friend class ::blink::CSSValuePool;
 

third_party/blink/renderer/core/inspector/inspector_css_agent.cc

@@ -2356,7 +2356,7 @@ Response InspectorCSSAgent::getBackgroundColors(
   *background_colors = protocol::Array<String>::create();
   for (auto color : colors) {
     background_colors->fromJust()->addItem(
-        color.SerializedAsCSSComponentValue());
+        cssvalue::CSSColorValue::SerializeAsCSSComponentValue(color));
   }
 
   CSSComputedStyleDeclaration* computed_style_info =

third_party/blink/renderer/core/svg/svg_animated_color.cc

@@ -19,6 +19,7 @@
 
 #include "third_party/blink/renderer/core/svg/svg_animated_color.h"
 
+#include "third_party/blink/renderer/core/css/css_color_value.h"
 #include "third_party/blink/renderer/core/css/parser/css_parser.h"
 #include "third_party/blink/renderer/core/layout/layout_object.h"
 #include "third_party/blink/renderer/core/svg/color_distance.h"
@@ -36,7 +37,8 @@ SVGColorProperty::SVGColorProperty(const String& color_string)
 String SVGColorProperty::ValueAsString() const {
   return style_color_.IsCurrentColor()
              ? "currentColor"
-             : style_color_.GetColor().SerializedAsCSSComponentValue();
+             : cssvalue::CSSColorValue::SerializeAsCSSComponentValue(
+                   style_color_.GetColor());
 }
 
 SVGPropertyBase* SVGColorProperty::CloneForAnimation(const String&) const {

third_party/blink/renderer/platform/graphics/color.cc

@@ -225,40 +225,6 @@ bool Color::SetFromString(const String& name) {
   return ParseHexColor(name.Characters16() + 1, name.length() - 1, color_);
 }
 
-String Color::SerializedAsCSSComponentValue() const {
-  StringBuilder result;
-  result.ReserveCapacity(32);
-  bool color_has_alpha = HasAlpha();
-  if (color_has_alpha)
-    result.Append("rgba(");
-  else
-    result.Append("rgb(");
-
-  result.AppendNumber(static_cast<unsigned char>(Red()));
-  result.Append(", ");
-
-  result.AppendNumber(static_cast<unsigned char>(Green()));
-  result.Append(", ");
-
-  result.AppendNumber(static_cast<unsigned char>(Blue()));
-  if (color_has_alpha) {
-    result.Append(", ");
-    // See <alphavalue> section in
-    // https://drafts.csswg.org/cssom/#serializing-css-values
-    int alphavalue = Alpha();
-    float rounded = round(alphavalue * 100 / 255.0f) / 100;
-    if (round(rounded * 255) == alphavalue) {
-      result.AppendNumber(rounded, 2);
-    } else {
-      rounded = round(alphavalue * 1000 / 255.0f) / 1000;
-      result.AppendNumber(rounded, 3);
-    }
-  }
-
-  result.Append(')');
-  return result.ToString();
-}
-
 String Color::Serialized() const {
   if (!HasAlpha()) {
     StringBuilder builder;

third_party/blink/renderer/platform/graphics/color.h

@@ -97,10 +97,6 @@ class PLATFORM_EXPORT Color {
   // http://www.whatwg.org/specs/web-apps/current-work/#serialization-of-a-color
   String Serialized() const;
 
-  // Returns the color serialized according to CSSOM:
-  // https://drafts.csswg.org/cssom/#serialize-a-css-component-value
-  String SerializedAsCSSComponentValue() const;
-
   // Returns the color serialized as either #RRGGBB or #RRGGBBAA. The latter
   // format is not a valid CSS color, and should only be seen in DRT dumps.
   String NameForLayoutTreeAsText() const;