Make content::FeaturePolicy implement WebFeaturePolicy, and use it in blink code

content/child/blink_platform_impl.cc

Index: content/child/blink_platform_impl.cc
diff --git a/content/child/blink_platform_impl.cc b/content/child/blink_platform_impl.cc
index b2b964a690c121637c09c5e9385c0e7f1378518e..db93f9b79f09853efe6162f49ac52ffa6a6a2883 100644
--- a/content/child/blink_platform_impl.cc
+++ b/content/child/blink_platform_impl.cc
@@ -39,6 +39,7 @@
 #include "content/app/strings/grit/content_strings.h"
 #include "content/child/child_thread_impl.h"
 #include "content/child/content_child_helpers.h"
+#include "content/child/feature_policy/feature_policy_platform.h"
 #include "content/child/notifications/notification_dispatcher.h"
 #include "content/child/notifications/notification_manager.h"
 #include "content/child/push_messaging/push_provider.h"
@@ -850,4 +851,28 @@ int BlinkPlatformImpl::domKeyEnumFromString(const WebString& key_string) {
       ui::KeycodeConverter::KeyStringToDomKey(key_string.utf8()));
 }
 
+blink::WebFeaturePolicy* BlinkPlatformImpl::createFeaturePolicy(
+    const blink::WebFeaturePolicy* parent_policy,
+    const blink::WebParsedFeaturePolicyHeader& container_policy,
+    const blink::WebParsedFeaturePolicyHeader& policy_header,
+    const blink::WebSecurityOrigin& origin) {
+  std::unique_ptr<FeaturePolicy> policy = FeaturePolicy::CreateFromParentPolicy(
+      static_cast<const FeaturePolicy*>(parent_policy),
+      FeaturePolicyHeaderFromWeb(container_policy), url::Origin(origin));
+  policy->SetHeaderPolicy(FeaturePolicyHeaderFromWeb(policy_header));
+  return policy.release();
+}
+
+bool BlinkPlatformImpl::isFeatureEnabledByPolicy(
+    const blink::WebFeaturePolicy* policy,
+    blink::WebFeaturePolicyFeature feature) {
+  return static_cast<const FeaturePolicy*>(policy)->IsFeatureEnabled(feature);

[haraken, 2017/02/28 06:41:43]

Hmm, it looks a bit weird that we're redirecting a Platform's method to
WebFeaturePolicy's method using a static cast.

Can we move createFeaturePolicy, isFeatureEnabledByPolicy and
updateFeaturePolicyOrigin to WebFeaturePolicy?

[iclelland, 2017/02/28 21:02:39]

I can move isFeatureEnabledByPolicy and updateFeaturePolicyOrigin to virtual
methods on WebFeaturePolicy; I think that makes sense.

createFeaturePolicy is necessarily a static method, so it's not something that
would be easily implemented by subclasses. It makes sense to make it a platform
responsibility to create an appropriate FeaturePolicy object on request, and
then that object implements the other methods (isFeatureEnabled, updateOrigin).
WDYT?

+}
+
+void BlinkPlatformImpl::updateFeaturePolicyOrigin(
+    blink::WebFeaturePolicy* policy,
+    const blink::WebSecurityOrigin& origin) {
+  static_cast<FeaturePolicy*>(policy)->SetOrigin(url::Origin(origin));
+}
+
 }  // namespace content