Mark CryptoKey and SubtleCrypto interfaces as SecureContext.

This matches the IDL from the spec, and resolves a bug whereby the Web Crypto API could be used from an insecure context.

We were correctly blocking access to "self.crypto.subtle" from insecure contexts, however it was possible to access through its interface self.SubtleCrypto.

Bug: 1038704
Change-Id: I425d602fda64c3f63ee87bcfed1711e508901c61
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2057098
Commit-Queue: Eric Roman <eroman@chromium.org>
Reviewed-by: Philip Jägenstedt <foolip@chromium.org>
Cr-Commit-Position: refs/heads/master@{#743242}

third_party/blink/renderer/modules/crypto/crypto_key.idl

@@ -31,6 +31,7 @@
 // https://w3c.github.io/webcrypto/Overview.html#cryptokey-interface
 
 [
+    SecureContext,
     Exposed=(Window,Worker)
 ] interface CryptoKey {
     readonly attribute DOMString type;

third_party/blink/renderer/modules/crypto/subtle_crypto.idl

@@ -35,6 +35,7 @@ typedef DOMString KeyUsage;
 typedef (Dictionary or DOMString) AlgorithmIdentifier;
 
 [
+    SecureContext,
     Exposed=(Window,Worker)
 ] interface SubtleCrypto {
     [CallWith=ScriptState, MeasureAs=SubtleCryptoEncrypt] Promise<any> encrypt(AlgorithmIdentifier algorithm, CryptoKey key, BufferSource data);

third_party/blink/web_tests/external/wpt/WebCryptoAPI/historical.any-expected.txt

-This is a testharness.js-based test.
-PASS Non-secure context window does not have access to crypto.subtle
-FAIL Non-secure context window does not have access to SubtleCrypto assert_equals: expected (undefined) undefined but got (function) function "function SubtleCrypto() { [native code] }"
-FAIL Non-secure context window does not have access to CryptoKey assert_equals: expected (undefined) undefined but got (function) function "function CryptoKey() { [native code] }"
-Harness: the test ran to completion.
-

third_party/blink/web_tests/external/wpt/WebCryptoAPI/historical.any.sharedworker-expected.txt

-This is a testharness.js-based test.
-PASS Non-secure context window does not have access to crypto.subtle
-FAIL Non-secure context window does not have access to SubtleCrypto assert_equals: expected (undefined) undefined but got (function) function "function SubtleCrypto() { [native code] }"
-FAIL Non-secure context window does not have access to CryptoKey assert_equals: expected (undefined) undefined but got (function) function "function CryptoKey() { [native code] }"
-Harness: the test ran to completion.
-

third_party/blink/web_tests/external/wpt/WebCryptoAPI/historical.any.worker-expected.txt

-This is a testharness.js-based test.
-PASS Non-secure context window does not have access to crypto.subtle
-FAIL Non-secure context window does not have access to SubtleCrypto assert_equals: expected (undefined) undefined but got (function) function "function SubtleCrypto() { [native code] }"
-FAIL Non-secure context window does not have access to CryptoKey assert_equals: expected (undefined) undefined but got (function) function "function CryptoKey() { [native code] }"
-Harness: the test ran to completion.
-