[WebCrypto] Use Deprecation instead of UseCounter

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

Index: third_party/WebKit/Source/core/frame/Deprecation.cpp
diff --git a/third_party/WebKit/Source/core/frame/Deprecation.cpp b/third_party/WebKit/Source/core/frame/Deprecation.cpp
index 86fb5c497dfb42031fc250d11f9a925027eb4728..f5bf16d3ed48712a71c82f117d4ba626b1cf48ad 100644
--- a/third_party/WebKit/Source/core/frame/Deprecation.cpp
+++ b/third_party/WebKit/Source/core/frame/Deprecation.cpp
@@ -423,6 +423,13 @@ String Deprecation::deprecationMessage(UseCounter::Feature feature) {
              "https://www.chromestatus.com/features/6680566019653632 for more "
              "details.";
 
+    case UseCounter::SubtleCryptoOnlyStrictSecureContextCheckFailed:
+      return String::format(
+          "Web Crypto API usage inside secure frames with non-secure ancestors "
+          "is deprecated. The API will no longer be exposed in these contexts "
+          "as of %s. See https://www.chromestatus.com/features/5030265697075200"
+          " for more details.", milestoneString(M59));
+
     // Features that aren't deprecated don't have a deprecation message.
     default:
       return String();