Fix a WebCrypto error type: InvalidAccessError --> OperationError.

content/test/data/webcrypto/ecdh.json

 // TODO(eroman): Use known test vectors. The samples I used here I generated myself.
 [
   // Test key derivation using ECDH (P-256), using a public and private key from
   // different key pairs.
   {
     "public_key": {
       "crv": "P-256",
       "kty":"EC",
       "x":"u6dWhaRHrvFF0CiFVuUUFafU6ixveQf9trHDXJ8hgV8",
       "y":"thSm4LIY35vDD-5LE454eB7TShn919DVVGZ_7tWdjTE"
@@ skipping 257 matching lines @@
       "d":"CQ8uF_-zB1NftLO6ytwKM3Cnuol64PQw5qOuCzQJeFU"
     },
     "public_key": {
       "kty":"EC",
       "crv":"P-256",
       "x":"S2S3tjygMB0DkM-N9jYUgGLt_9_H6km5P9V6V_KS4_4",
       "y":"03j8Tyqgrc4R4FAUV2C7-im96yMmfmO_5Om6Kr8YP3o"
     },
 
     "length_bits": 257,
-    "error": "InvalidAccess: Length specified for ECDH key derivation is too large. Maximum allowed is 256 bits"
+    "error": "OperationError: Length specified for ECDH key derivation is too large. Maximum allowed is 256 bits"
   },
 
   // The length is too long, by 1 byte
   {
     "private_key": {
       "kty":"EC",
       "crv":"P-256",
       "x":"u6dWhaRHrvFF0CiFVuUUFafU6ixveQf9trHDXJ8hgV8",
       "y":"thSm4LIY35vDD-5LE454eB7TShn919DVVGZ_7tWdjTE",
       "d":"CQ8uF_-zB1NftLO6ytwKM3Cnuol64PQw5qOuCzQJeFU"
     },
     "public_key": {
       "kty":"EC",
       "crv":"P-256",
       "x":"S2S3tjygMB0DkM-N9jYUgGLt_9_H6km5P9V6V_KS4_4",
       "y":"03j8Tyqgrc4R4FAUV2C7-im96yMmfmO_5Om6Kr8YP3o"
     },
 
     "length_bits": 264,
-    "error": "InvalidAccess: Length specified for ECDH key derivation is too large. Maximum allowed is 256 bits"
+    "error": "OperationError: Length specified for ECDH key derivation is too large. Maximum allowed is 256 bits"
   },
 
   // The public key parameter is in fact a private key
   // (not allowed by web crypto), even though it could in practice work.
   {
     "private_key": {
       "kty":"EC",
       "crv":"P-256",
       "x":"u6dWhaRHrvFF0CiFVuUUFafU6ixveQf9trHDXJ8hgV8",
       "y":"thSm4LIY35vDD-5LE454eB7TShn919DVVGZ_7tWdjTE",
@@ skipping 43 matching lines @@
 
     "private_key": {
       "crv":"P-521",
       "kty":"EC",
       "d":"AU3LVJK4dtlbOEFb018ry-D-kYF7J7oQxXLpXcnQXbTh42FORGGGtySTA83gT_GiHJ0tnvgVrDdUMK1muJBGPrRf",
       "x":"ADRllQ0B7icrnJ7ib2r-CXvymGFiC_3f6_o0SzLMBIggM8ndQm9l768SToMy1hUo64JsofGSQ37P4CRqT_QeivBD",
       "y":"ALKEzew1Xe4Sv86lZVqb2xxZ0l7WrE3DPJ93fUtSPih5iH8jg0GPDKMVoA5ffFmqPwbdgS2BK18PBFIT7QDGb2Zx"
     },
 
     "length_bits": 529,
-    "error": "InvalidAccess: Length specified for ECDH key derivation is too large. Maximum allowed is 528 bits"
+    "error": "OperationError: Length specified for ECDH key derivation is too large. Maximum allowed is 528 bits"
   }
 ]