Remove unmaintained third-party safemem crate

third_party/rust/Cargo.toml

@@ -1029,10 +1029,6 @@ package = "rustversion"
 path = "../../../third_party/rust/ryu/v1/crate"
 package = "ryu"
 
-[patch.crates-io.safemem_v0_3]
-path = "safemem/v0_3/crate"
-package = "safemem"
-
 [patch.crates-io.scopeguard_v1]
 path = "scopeguard/v1/crate"
 package = "scopeguard"

third_party/rust/lol_html/v0_3/BUILD.gn

@@ -126,7 +126,6 @@ cargo_crate("lib") {
     "//brave/third_party/rust/encoding_rs/v0_8:lib",
     "//brave/third_party/rust/hashbrown/v0_12:lib",
     "//brave/third_party/rust/lazycell/v1:lib",
-    "//brave/third_party/rust/safemem/v0_3:lib",
     "//brave/third_party/rust/selectors/v0_22:lib",
     "//brave/third_party/rust/thiserror/v1:lib",
     "//third_party/rust/bitflags/v1:lib",

third_party/rust/lol_html/v0_3/crate/Cargo.toml

@@ -76,9 +76,6 @@ version = "1.3.0"
 [dependencies.memchr]
 version = "2.1.2"
 
-[dependencies.safemem]
-version = "0.3.3"
-
 [dependencies.selectors]
 version = "0.22.0"
 

third_party/rust/lol_html/v0_3/crate/src/memory/arena.rs

@@ -1,5 +1,4 @@
 use super::{MemoryLimitExceededError, SharedMemoryLimiter};
-use safemem::copy_over;
 
 /// Preallocated region of memory that can grow and never deallocates during the lifetime of
 /// the limiter.
@@ -48,10 +47,8 @@ impl Arena {
     }
 
     pub fn shift(&mut self, byte_count: usize) {
-        let remainder_len = self.data.len() - byte_count;
-
-        copy_over(&mut self.data, byte_count, 0, remainder_len);
-        self.data.truncate(remainder_len);
+        self.data.copy_within(byte_count.., 0);
+        self.data.truncate(self.data.len() - byte_count);
     }
 
     pub fn bytes(&self) -> &[u8] {