Clear some reported gcc -Wshadow warnings.

The constructor parameter vs. method name one is a little unfortunate
given Google C++ style, but I think we've done this elsewhere in libssl,
so let's run with it for now.

Bug: 378
Change-Id: I31fb6b4b16e3248369dae6f47cc150de0e4f04fe
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/43545
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>

crypto/trust_token/trust_token_test.cc

@@ -134,8 +134,8 @@ static std::vector<const TRUST_TOKEN_METHOD *> AllMethods() {
 
 class TrustTokenProtocolTestBase : public ::testing::Test {
  public:
-  explicit TrustTokenProtocolTestBase(const TRUST_TOKEN_METHOD *method)
-      : method_(method) {}
+  explicit TrustTokenProtocolTestBase(const TRUST_TOKEN_METHOD *method_arg)
+      : method_(method_arg) {}
 
   // KeyID returns the key ID associated with key index |i|.
   static uint32_t KeyID(size_t i) {
@@ -638,13 +638,13 @@ TEST_P(TrustTokenMetadataTest, TruncatedProof) {
   CBS real_response;
   CBS_init(&real_response, issue_resp, resp_len);
   uint16_t count;
-  uint32_t public_metadata;
+  uint32_t parsed_public_metadata;
   bssl::ScopedCBB bad_response;
   ASSERT_TRUE(CBB_init(bad_response.get(), 0));
   ASSERT_TRUE(CBS_get_u16(&real_response, &count));
   ASSERT_TRUE(CBB_add_u16(bad_response.get(), count));
-  ASSERT_TRUE(CBS_get_u32(&real_response, &public_metadata));
-  ASSERT_TRUE(CBB_add_u32(bad_response.get(), public_metadata));
+  ASSERT_TRUE(CBS_get_u32(&real_response, &parsed_public_metadata));
+  ASSERT_TRUE(CBB_add_u32(bad_response.get(), parsed_public_metadata));
 
   const EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp384r1);
   size_t token_length =
@@ -701,13 +701,13 @@ TEST_P(TrustTokenMetadataTest, ExcessDataProof) {
   CBS real_response;
   CBS_init(&real_response, issue_resp, resp_len);
   uint16_t count;
-  uint32_t public_metadata;
+  uint32_t parsed_public_metadata;
   bssl::ScopedCBB bad_response;
   ASSERT_TRUE(CBB_init(bad_response.get(), 0));
   ASSERT_TRUE(CBS_get_u16(&real_response, &count));
   ASSERT_TRUE(CBB_add_u16(bad_response.get(), count));
-  ASSERT_TRUE(CBS_get_u32(&real_response, &public_metadata));
-  ASSERT_TRUE(CBB_add_u32(bad_response.get(), public_metadata));
+  ASSERT_TRUE(CBS_get_u32(&real_response, &parsed_public_metadata));
+  ASSERT_TRUE(CBB_add_u32(bad_response.get(), parsed_public_metadata));
 
   const EC_GROUP *group = EC_GROUP_new_by_curve_name(NID_secp384r1);
   size_t token_length =