V8 bindings gen: Error if OriginTrialEnabled and SecureContext together.

third_party/WebKit/Source/modules/serviceworkers/NavigationPreloadManager.idl

Index: third_party/WebKit/Source/modules/serviceworkers/NavigationPreloadManager.idl
diff --git a/third_party/WebKit/Source/modules/serviceworkers/NavigationPreloadManager.idl b/third_party/WebKit/Source/modules/serviceworkers/NavigationPreloadManager.idl
index 6664c77b55a0dc3b6598c5828a451ca6d408004d..8130f1d4e26d7abb2d7674432ab8176fc6b45dc7 100644
--- a/third_party/WebKit/Source/modules/serviceworkers/NavigationPreloadManager.idl
+++ b/third_party/WebKit/Source/modules/serviceworkers/NavigationPreloadManager.idl
@@ -6,11 +6,10 @@
 // https://github.com/w3c/ServiceWorker/issues/920
 [
     OriginTrialEnabled=ServiceWorkerNavigationPreload,
-    SecureContext,
     Exposed=(Window,Worker),
 ] interface NavigationPreloadManager {
-    [CallWith=ScriptState] Promise<void> enable();
-    [CallWith=ScriptState] Promise<void> disable();
-    [CallWith=ScriptState] Promise<void> setHeaderValue(ByteString value);
-    [CallWith=ScriptState] Promise<NavigationPreloadState> getState();
+    [SecureContext, CallWith=ScriptState] Promise<void> enable();

[Matt Giuca, 2017/03/29 06:24:37]

Oh no this is awful.

It turns out that NavigationPreloadManager is hitting the new error because it
uses OTE and SC at the same time. But this isn't actually a problem because the
SC is being automatically applied to all the members of NavigationPreloadManager
(not the class itself), and the class itself is being registered manually.

If I move the SecureContext down here to all the methods, it doesn't hit the
check and seems to generate the same code.

Is this acceptable?

[Yuki, 2017/03/29 06:38:06]

Just a question, why NavigationPreloadManager is OriginTrialEnabled?
If it's because it's not yet stable and we'd like to expose the APIs to limited
users and we're planning to remove [OriginTrialEnabled], it makes a sense.

However, with this change, we're going to expose NavigationPreloadManager
interface itself as long as the origin trial is specified even when it's not a
secure context.

Should we expose NavigationPreloadManager only when the origin trial is
specified *and* it's a secure context?

https://w3c.github.io/ServiceWorker/#navigation-preload-manager
The spec seems saying we shouldn't expose the interface if it's not a secure
context.

[falken, 2017/03/29 06:43:45]

Yes, NavigationPreloadManager is an experimental feature that is in an origin
trial. The feature should only be exposed in secure contexts.

[Matt Giuca, 2017/03/30 02:57:28]

I would be changing the IDL away from the spec, but it has the same effect in
Chrome (the NavigationPreloadManager object itself is still available in a
non-secure context, just not the methods). I can add a comment saying this is a
work-around this bug.

+    [SecureContext, CallWith=ScriptState] Promise<void> disable();
+    [SecureContext, CallWith=ScriptState] Promise<void> setHeaderValue(ByteString value);
+    [SecureContext, CallWith=ScriptState] Promise<NavigationPreloadState> getState();
 };