[SVGDom] Add <svg> viewBox support

experimental/svg/model/SkSVGAttributeParser.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkParse.h"
 #include "SkSVGAttributeParser.h"
 #include "SkSVGTypes.h"
@@ skipping 131 matching lines @@
         break;
     default:
         return false;
     }
 
     *c = v | 0xff000000;
     return true;
 }
 
 // https://www.w3.org/TR/SVG/types.html#DataTypeColor
-bool SkSVGAttributeParser::parseColor(SkSVGColor* color) {
+bool SkSVGAttributeParser::parseColor(SkSVGColorType* color) {
     SkColor c;
 
     // TODO: rgb(...)
     if (this->parseHexColorToken(&c) || this->parseNamedColorToken(&c)) {
-        *color = SkSVGColor(c);
+        *color = SkSVGColorType(c);
         return true;
     }
 
     return false;
 }
 
 // https://www.w3.org/TR/SVG/types.html#DataTypeNumber
-bool SkSVGAttributeParser::parseNumber(SkSVGNumber* number) {
+bool SkSVGAttributeParser::parseNumber(SkSVGNumberType* number) {
     // consume WS
     this->parseWSToken();
 
     SkScalar s;
     if (this->parseScalarToken(&s)) {
-        *number = SkSVGNumber(s);
+        *number = SkSVGNumberType(s);
         // consume trailing separators
         this->parseSepToken();
         return true;
     }
 
     return false;
 }
 
 // https://www.w3.org/TR/SVG/types.html#DataTypeLength
 bool SkSVGAttributeParser::parseLength(SkSVGLength* length) {
     SkScalar s;
     SkSVGLength::Unit u = SkSVGLength::Unit::kNumber;
 
     if (this->parseScalarToken(&s) &&
         (this->parseLengthUnitToken(&u) || this->parseSepToken() || this->parseEOSToken())) {
         *length = SkSVGLength(s, u);
         // consume trailing separators
         this->parseSepToken();
         return true;
     }
 
     return false;
 }
+
+// https://www.w3.org/TR/SVG/coords.html#ViewBoxAttribute
+bool SkSVGAttributeParser::parseViewBox(SkSVGViewBoxType* vb) {
+    SkScalar x, y, w, h;
+    this->parseWSToken();
+
+    bool parsedValue = false;
+    if (this->parseScalarToken(&x) && this->parseSepToken() &&
+        this->parseScalarToken(&y) && this->parseSepToken() &&
+        this->parseScalarToken(&w) && this->parseSepToken() &&
+        this->parseScalarToken(&h)) {
+
+        *vb = SkSVGViewBoxType(SkRect::MakeXYWH(x, y, w, h));
+        parsedValue = true;
+        // consume trailing whitespace
+        this->parseWSToken();
+    }
+    return parsedValue && this->parseEOSToken();
+}