Remove residual support for SHA-1 public key pins.

net/base/hash_value.cc

Index: net/base/hash_value.cc
diff --git a/net/base/hash_value.cc b/net/base/hash_value.cc
index 0f109405ae4a4208d827d737c10b13fff151ebcd..d7170ca0fee951bb397c73a895af2d44e3bab653 100644
--- a/net/base/hash_value.cc
+++ b/net/base/hash_value.cc
@@ -37,10 +37,7 @@ HashValue::HashValue(const SHA256HashValue& hash)
 
 bool HashValue::FromString(const base::StringPiece value) {
   base::StringPiece base64_str;
-  if (value.starts_with("sha1/")) {
-    tag = HASH_VALUE_SHA1;
-    base64_str = value.substr(5);
-  } else if (value.starts_with("sha256/")) {
+  if (value.starts_with("sha256/")) {
     tag = HASH_VALUE_SHA256;
     base64_str = value.substr(7);
   } else {