Fix 26 ClangTidy - Readability findings in //depot/google3/third_party/quic/.

These fixes are automatically created by various analysis tools, but their application in this CL has been manually triggered.  See go/code-findings-fixes.

* redundant get() call on smart pointer (11 times)
* using decl 'Perspective' is unused
* using decl 'SETTINGS_MAX_HEADER_LIST_SIZE' is unused (2 times)
* using decl 'AtLeast' is unused
* using decl 'SpdySettingsIR' is unused
* using decl 'Pair' is unused
* using decl 'UnorderedElementsAre' is unused
* using decl 'Values' is unused
* using decl 'Combine' is unused
* using decl 'Invoke' is unused
* lambda capture 'this' is not used (4 times)
* using decl 'QuicSocketAddress' is unused

PiperOrigin-RevId: 276529025
Change-Id: Icee20b5bab6c9d8cc6c95b74594469257e791cb0
diff --git a/quic/core/crypto/quic_crypto_server_config.cc b/quic/core/crypto/quic_crypto_server_config.cc
index c211cdb..c23cf0f 100644
--- a/quic/core/crypto/quic_crypto_server_config.cc
+++ b/quic/core/crypto/quic_crypto_server_config.cc
@@ -385,14 +385,14 @@
   std::unique_ptr<CryptoHandshakeMessage> msg =
       CryptoFramer::ParseMessage(protobuf.config());
 
-  if (!msg.get()) {
+  if (!msg) {
     QUIC_LOG(WARNING) << "Failed to parse server config message";
     return nullptr;
   }
 
   QuicReferenceCountedPointer<Config> config =
       ParseConfigProtobuf(protobuf, /* is_fallback = */ false);
-  if (!config.get()) {
+  if (!config) {
     QUIC_LOG(WARNING) << "Failed to parse server config message";
     return nullptr;
   }
@@ -896,7 +896,7 @@
     }
     std::unique_ptr<CryptoHandshakeMessage> cetv(CryptoFramer::ParseMessage(
         QuicStringPiece(plaintext, plaintext_length)));
-    if (!cetv.get()) {
+    if (!cetv) {
       context->Fail(QUIC_INVALID_CRYPTO_MESSAGE_PARAMETER, "CETV parse error");
       return;
     }