Initial Implementation of Iframe Attribute for Feature Policy (Part 1)

third_party/WebKit/Source/core/html/HTMLIFrameElementAllow.cpp

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/html/HTMLIFrameElementAllow.h"
+
+#include "core/html/HTMLIFrameElement.h"
+#include "platform/feature_policy/FeaturePolicy.h"
+
+using blink::WebFeaturePolicyFeature;
+
+namespace blink {
+
+HTMLIFrameElementAllow::HTMLIFrameElementAllow(HTMLIFrameElement* element)
+    : DOMTokenList(this), m_element(element) {}
+
+HTMLIFrameElementAllow::~HTMLIFrameElementAllow() {}
+
+DEFINE_TRACE(HTMLIFrameElementAllow) {
+  visitor->trace(m_element);
+  DOMTokenList::trace(visitor);
+  DOMTokenListObserver::trace(visitor);
+}
+
+Vector<WebFeaturePolicyFeature>
+HTMLIFrameElementAllow::parseAllowedFeatureNames(
+    String& invalidTokensErrorMessage) const {
+  Vector<WebFeaturePolicyFeature> featureNames;
+  Vector<WebFeaturePolicyFeature> allowedFeatureNames;
+  unsigned numTokenErrors = 0;
+  StringBuilder tokenErrors;
+  const SpaceSplitString& tokens = this->tokens();
+
+  // Collects a list of valid feature names.
+  for (size_t i = 0; i < tokens.size(); ++i) {
+    WebFeaturePolicyFeature feature =
+        FeaturePolicy::getWebFeaturePolicyFeature(tokens[i]);
+    if (feature == WebFeaturePolicyFeature::NotFound) {
+      tokenErrors.append(tokenErrors.isEmpty() ? "'" : ", '");
+      tokenErrors.append(tokens[i]);
+      tokenErrors.append("'");
+      ++numTokenErrors;
+    } else {
+      featureNames.push_back(feature);
+    }
+  }
+
+  if (numTokenErrors) {
+    tokenErrors.append(numTokenErrors > 1 ? " are invalid feature names."
+                                          : " is an invalid feature name.");
+    invalidTokensErrorMessage = tokenErrors.toString();
+  }
+
+  // Create a unique set of feature names.
+  std::sort(featureNames.begin(), featureNames.end());
+  WebFeaturePolicyFeature lastFeature = WebFeaturePolicyFeature::NotFound;
+  for (auto const feature : featureNames) {

[jbroman, 2017/02/11 05:34:29]

nit: STL has an efficient uniqueness thing that is more efficient:

std::sort(featureNames.begin(), featureNames.end());
auto it = std::unique(featureNames.begin(), featureNames.end());
featureNames.shrink(featureNames.end() - it);
return featureNames;

// then allowedFeatureNames is redundant

[jbroman, 2017/02/11 05:36:09]

This line should be:

featureNames.shrink(it - featureNames.begin());

+    if (feature == lastFeature)
+      continue;
+    allowedFeatureNames.push_back(feature);
+    lastFeature = feature;
+  }
+
+  return allowedFeatureNames;
+}
+
+bool HTMLIFrameElementAllow::validateTokenValue(const AtomicString& tokenValue,
+                                                ExceptionState&) const {
+  return FeaturePolicy::getWebFeaturePolicyFeature(tokenValue.getString()) !=
+         WebFeaturePolicyFeature::NotFound;
+}
+
+void HTMLIFrameElementAllow::valueWasSet() {
+  DCHECK(m_element);
+  m_element->allowValueWasSet();
+}
+
+}  // namespace blink