DevTools: introduce spritesheet assembler.

third_party/WebKit/Source/devtools/scripts/spritesheet_assembler/SVGSprite.js

+var fs = require('fs');
+var sizeOf = require('image-size');
+
+class SVGSprite {
+  /**
+   * @param {string} filePath
+   * @param {string} content
+   * @param {number} width
+   * @param {number} height
+   */
+  constructor(filePath, content, width, height) {
+    this.filePath = filePath;
+    this.content = content;
+    this.width = width;
+    this.height = height;
+  }
+
+  /**
+   * @param {string} filePath
+   * @return {!SVGSprite}
+   */
+  static loadFromFile(filePath) {
+    var content = fs.readFileSync(filePath, 'utf-8');
+    var dimensions = sizeOf(filePath);
+    return new SVGSprite(filePath, content, dimensions.width, dimensions.height);
+  }
+};
+
+module.exports = SVGSprite;