service worker: Don't control a subframe of an insecure context

third_party/WebKit/Source/core/frame/Frame.cpp

Index: third_party/WebKit/Source/core/frame/Frame.cpp
diff --git a/third_party/WebKit/Source/core/frame/Frame.cpp b/third_party/WebKit/Source/core/frame/Frame.cpp
index 3e1d8f5dc32177c475b9715771f81a1d8b05b666..600e126387fb094ec3d3baded04a10dbae5d6236 100644
--- a/third_party/WebKit/Source/core/frame/Frame.cpp
+++ b/third_party/WebKit/Source/core/frame/Frame.cpp
@@ -305,6 +305,15 @@ void Frame::didChangeVisibilityState()
         childFrames[i]->didChangeVisibilityState();
 }
 
+bool Frame::canHaveSecureChild(String* errorMessage) const
+{
+    for (const Frame* parent = this; parent; parent = parent->tree().parent()) {
+        if (!parent->securityContext()->getSecurityOrigin()->isPotentiallyTrustworthy(errorMessage))
+            return false;
+    }
+    return true;
+}
+
 Frame::Frame(FrameClient* client, FrameHost* host, FrameOwner* owner)
     : m_treeNode(this)
     , m_host(host)