Measure impact of [SecureContext] on WebCrypto.

third_party/WebKit/Source/modules/crypto/SubtleCrypto.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "modules/crypto/SubtleCrypto.h"
 
 #include "bindings/core/v8/Dictionary.h"
 #include "core/dom/DOMArrayBuffer.h"
 #include "core/dom/DOMArrayBufferView.h"
 #include "core/dom/DOMArrayPiece.h"
 #include "core/dom/ExecutionContext.h"
+#include "core/frame/UseCounter.h"
 #include "modules/crypto/CryptoHistograms.h"
 #include "modules/crypto/CryptoKey.h"
 #include "modules/crypto/CryptoResultImpl.h"
 #include "modules/crypto/NormalizeAlgorithm.h"
 #include "platform/json/JSONValues.h"
 #include "public/platform/Platform.h"
 #include "public/platform/WebCrypto.h"
 #include "public/platform/WebCryptoAlgorithm.h"
 
 namespace blink {
@@ skipping 10 matching lines @@
 }
 
 static bool canAccessWebCrypto(ScriptState* scriptState, CryptoResult* result) {
   String errorMessage;
   if (!scriptState->getExecutionContext()->isSecureContext(
           errorMessage, ExecutionContext::WebCryptoSecureContextCheck)) {
     result->completeWithError(WebCryptoErrorTypeNotSupported, errorMessage);
     return false;
   }
 
+  if (!scriptState->getExecutionContext()->isSecureContext()) {
+    UseCounter::count(
+        scriptState->getExecutionContext(),
+        UseCounter::SubtleCryptoOnlyStrictSecureContextCheckFailed);
+  }
+
   return true;
 }
 
 static bool copyStringProperty(const char* property,
                                const Dictionary& source,
                                JSONObject* destination) {
   String value;
   if (!DictionaryHelper::get(source, property, value))
     return false;
   destination->setString(property, value);
@@ skipping 687 matching lines @@
                            normalizedAlgorithm, baseKey->key());
   histogramAlgorithm(scriptState->getExecutionContext(),
                      normalizedDerivedKeyAlgorithm);
   Platform::current()->crypto()->deriveKey(
       normalizedAlgorithm, baseKey->key(), normalizedDerivedKeyAlgorithm,
       keyLengthAlgorithm, extractable, keyUsages, result->result());
   return promise;
 }
 
 }  // namespace blink