webcrypto: remove cross-thread cancellation checking.

components/webcrypto/webcrypto_impl.cc

Index: components/webcrypto/webcrypto_impl.cc
diff --git a/components/webcrypto/webcrypto_impl.cc b/components/webcrypto/webcrypto_impl.cc
index 3ccfbc912d1570201b575c33aa6ef57d0b718582..5afba8828cccd43a661a48a21a4808a8e8405984 100644
--- a/components/webcrypto/webcrypto_impl.cc
+++ b/components/webcrypto/webcrypto_impl.cc
@@ -162,8 +162,6 @@ struct BaseState {
   explicit BaseState(const blink::WebCryptoResult& result)
       : origin_thread(GetCurrentBlinkThread()), result(result) {}
 
-  bool cancelled() { return result.cancelled(); }
-
   scoped_refptr<base::TaskRunner> origin_thread;
 
   webcrypto::Status status;
@@ -380,8 +378,6 @@ void DoEncryptReply(scoped_ptr<EncryptState> state) {
 
 void DoEncrypt(scoped_ptr<EncryptState> passed_state) {
   EncryptState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status =
       webcrypto::Encrypt(state->algorithm, state->key,
                          webcrypto::CryptoData(state->data), &state->buffer);
@@ -395,8 +391,6 @@ void DoDecryptReply(scoped_ptr<DecryptState> state) {
 
 void DoDecrypt(scoped_ptr<DecryptState> passed_state) {
   DecryptState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status =
       webcrypto::Decrypt(state->algorithm, state->key,
                          webcrypto::CryptoData(state->data), &state->buffer);
@@ -410,8 +404,6 @@ void DoDigestReply(scoped_ptr<DigestState> state) {
 
 void DoDigest(scoped_ptr<DigestState> passed_state) {
   DigestState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status = webcrypto::Digest(
       state->algorithm, webcrypto::CryptoData(state->data), &state->buffer);
   state->origin_thread->PostTask(
@@ -428,8 +420,6 @@ void DoGenerateKeyReply(scoped_ptr<GenerateKeyState> state) {
 
 void DoGenerateKey(scoped_ptr<GenerateKeyState> passed_state) {
   GenerateKeyState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status =
       webcrypto::GenerateKey(state->algorithm, state->extractable,
                              state->usages, &state->generate_key_result);
@@ -443,8 +433,6 @@ void DoImportKeyReply(scoped_ptr<ImportKeyState> state) {
 
 void DoImportKey(scoped_ptr<ImportKeyState> passed_state) {
   ImportKeyState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status = webcrypto::ImportKey(
       state->format, webcrypto::CryptoData(state->key_data), state->algorithm,
       state->extractable, state->usages, &state->key);
@@ -475,8 +463,6 @@ void DoExportKeyReply(scoped_ptr<ExportKeyState> state) {
 
 void DoExportKey(scoped_ptr<ExportKeyState> passed_state) {
   ExportKeyState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status =
       webcrypto::ExportKey(state->format, state->key, &state->buffer);
   state->origin_thread->PostTask(
@@ -489,8 +475,6 @@ void DoSignReply(scoped_ptr<SignState> state) {
 
 void DoSign(scoped_ptr<SignState> passed_state) {
   SignState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status =
       webcrypto::Sign(state->algorithm, state->key,
                       webcrypto::CryptoData(state->data), &state->buffer);
@@ -509,8 +493,6 @@ void DoVerifyReply(scoped_ptr<VerifySignatureState> state) {
 
 void DoVerify(scoped_ptr<VerifySignatureState> passed_state) {
   VerifySignatureState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status = webcrypto::Verify(
       state->algorithm, state->key, webcrypto::CryptoData(state->signature),
       webcrypto::CryptoData(state->data), &state->verify_result);
@@ -525,8 +507,6 @@ void DoWrapKeyReply(scoped_ptr<WrapKeyState> state) {
 
 void DoWrapKey(scoped_ptr<WrapKeyState> passed_state) {
   WrapKeyState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status =
       webcrypto::WrapKey(state->format, state->key, state->wrapping_key,
                          state->wrap_algorithm, &state->buffer);
@@ -541,8 +521,6 @@ void DoUnwrapKeyReply(scoped_ptr<UnwrapKeyState> state) {
 
 void DoUnwrapKey(scoped_ptr<UnwrapKeyState> passed_state) {
   UnwrapKeyState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status = webcrypto::UnwrapKey(
       state->format, webcrypto::CryptoData(state->wrapped_key),
       state->wrapping_key, state->unwrap_algorithm,
@@ -560,8 +538,6 @@ void DoDeriveBitsReply(scoped_ptr<DeriveBitsState> state) {
 
 void DoDeriveBits(scoped_ptr<DeriveBitsState> passed_state) {
   DeriveBitsState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status =
       webcrypto::DeriveBits(state->algorithm, state->base_key,
                             state->length_bits, &state->derived_bytes);
@@ -575,8 +551,6 @@ void DoDeriveKeyReply(scoped_ptr<DeriveKeyState> state) {
 
 void DoDeriveKey(scoped_ptr<DeriveKeyState> passed_state) {
   DeriveKeyState* state = passed_state.get();
-  if (state->cancelled())
-    return;
   state->status = webcrypto::DeriveKey(
       state->algorithm, state->base_key, state->import_algorithm,
       state->key_length_algorithm, state->extractable, state->usages,