Added [SecureContext] to the subtle attribute

third_party/WebKit/Source/modules/crypto/Crypto.idl

Index: third_party/WebKit/Source/modules/crypto/Crypto.idl
diff --git a/third_party/WebKit/Source/modules/crypto/Crypto.idl b/third_party/WebKit/Source/modules/crypto/Crypto.idl
index 88f61462cb53b0b10d2c2c4a5f4833864ebe119f..01f7bc808c0d4e7d864ddb32b2c54f678e44fe9a 100644
--- a/third_party/WebKit/Source/modules/crypto/Crypto.idl
+++ b/third_party/WebKit/Source/modules/crypto/Crypto.idl
@@ -33,5 +33,5 @@
 ] interface Crypto {
     [RaisesException, MeasureAs=CryptoGetRandomValues] ArrayBufferView getRandomValues(ArrayBufferView array);
 
-    readonly attribute SubtleCrypto subtle;
+    [SecureContext] readonly attribute SubtleCrypto subtle;

[Mike West, 2017/04/24 14:19:22]

This should also let us remove a few other things:

1.  The `SecureContextCheck` enum from `ExecutionContext`, as I believe this API
is the only one that uses `kWebCryptoSecureContextCheck`. Since we'll now only
have one code-path, we can drop the enum entirely from the codebase.

2.  The `CanAccessWebCrypto` check from `SubtleCrypto.cpp` (you can replace it
with DCHECKs if you like, but I think we can just drop it entirely and rely on
the generated IDL checks).

3.  The `kSubtleCryptoOnlyStrictSecureContextCheckFailed` UseCounter enum value.

 };