Allow vibrate in cross-origin iframes with user gesture.

third_party/WebKit/Source/bindings/core/v8/ConditionalFeatures.cpp

Index: third_party/WebKit/Source/bindings/core/v8/ConditionalFeatures.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/ConditionalFeatures.cpp b/third_party/WebKit/Source/bindings/core/v8/ConditionalFeatures.cpp
index 6b28b52df4953a008dc110c22f6ab41c6b32a6e6..c47a54c0f8db487bfd4ad655a9496f11a53f1c5f 100644
--- a/third_party/WebKit/Source/bindings/core/v8/ConditionalFeatures.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/ConditionalFeatures.cpp
@@ -93,7 +93,7 @@ bool isFeatureEnabledInFrame(const FeaturePolicy::Feature& feature,
   bool enabledByDefault =
       (feature.defaultPolicy == FeaturePolicy::FeatureDefault::EnableForAll ||
        (feature.defaultPolicy == FeaturePolicy::FeatureDefault::EnableForSelf &&
-        !frame->isCrossOriginSubframe()));
+        (!frame->isCrossOriginSubframe() || frame->hasReceivedUserGesture())));

[ojan, 2017/01/22 23:02:54]

I don't think you want this here. This is the generic FeaturePolicy
implementation, which will eventually be exposed to web authors. This check
should go in NavigatorVibration.cpp for now. If we find it's more general, we
might want a helper function later.

   if (!RuntimeEnabledFeatures::featurePolicyEnabled() || !frame)
     return enabledByDefault;
   FeaturePolicy* featurePolicy = frame->securityContext()->getFeaturePolicy();