Add packages to optimize svgs dynamically

These packages will be used to dynamically optimize SVG images
during the build.

R=jacktfranklin@chromium.org

Bug: 1216402
Change-Id: I04e95aa7d79c9d67beaf8a7861182c52b16b7d0f
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2939992
Reviewed-by: Jack Franklin <jacktfranklin@chromium.org>
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
diff --git a/node_modules/css-tree/lib/lexer/trace.js b/node_modules/css-tree/lib/lexer/trace.js
new file mode 100644
index 0000000..3a45e53
--- /dev/null
+++ b/node_modules/css-tree/lib/lexer/trace.js
@@ -0,0 +1,79 @@
+function getTrace(node) {
+    function shouldPutToTrace(syntax) {
+        if (syntax === null) {
+            return false;
+        }
+
+        return (
+            syntax.type === 'Type' ||
+            syntax.type === 'Property' ||
+            syntax.type === 'Keyword'
+        );
+    }
+
+    function hasMatch(matchNode) {
+        if (Array.isArray(matchNode.match)) {
+            // use for-loop for better perfomance
+            for (var i = 0; i < matchNode.match.length; i++) {
+                if (hasMatch(matchNode.match[i])) {
+                    if (shouldPutToTrace(matchNode.syntax)) {
+                        result.unshift(matchNode.syntax);
+                    }
+
+                    return true;
+                }
+            }
+        } else if (matchNode.node === node) {
+            result = shouldPutToTrace(matchNode.syntax)
+                ? [matchNode.syntax]
+                : [];
+
+            return true;
+        }
+
+        return false;
+    }
+
+    var result = null;
+
+    if (this.matched !== null) {
+        hasMatch(this.matched);
+    }
+
+    return result;
+}
+
+function testNode(match, node, fn) {
+    var trace = getTrace.call(match, node);
+
+    if (trace === null) {
+        return false;
+    }
+
+    return trace.some(fn);
+}
+
+function isType(node, type) {
+    return testNode(this, node, function(matchNode) {
+        return matchNode.type === 'Type' && matchNode.name === type;
+    });
+}
+
+function isProperty(node, property) {
+    return testNode(this, node, function(matchNode) {
+        return matchNode.type === 'Property' && matchNode.name === property;
+    });
+}
+
+function isKeyword(node) {
+    return testNode(this, node, function(matchNode) {
+        return matchNode.type === 'Keyword';
+    });
+}
+
+module.exports = {
+    getTrace: getTrace,
+    isType: isType,
+    isProperty: isProperty,
+    isKeyword: isKeyword
+};