refactor: fix deprecated base::Base64Encode() API calls (#40962)

* refactor: replace deprecated Base64Encode() usage in IWC::NetworkResourceLoader::OnDataReceived()

* refactor: replace deprecated Base64Encode() usage EncodeToken(const base::UnguessableToken& token)

shell/browser/serial/serial_chooser_context.cc

@@ -38,11 +38,8 @@ const char kUsbDriverKey[] = "usb_driver";
 std::string EncodeToken(const base::UnguessableToken& token) {
   const uint64_t data[2] = {token.GetHighForSerialization(),
                             token.GetLowForSerialization()};
-  std::string buffer;
-  base::Base64Encode(
-      base::StringPiece(reinterpret_cast<const char*>(&data[0]), sizeof(data)),
-      &buffer);
-  return buffer;
+  return base::Base64Encode(
+      base::StringPiece(reinterpret_cast<const char*>(&data[0]), sizeof(data)));
 }
 
 base::Value PortInfoToValue(const device::mojom::SerialPortInfo& port) {

shell/browser/ui/inspectable_web_contents.cc

@@ -258,22 +258,11 @@ class InspectableWebContents::NetworkResourceLoader
 
   void OnDataReceived(base::StringPiece chunk,
                       base::OnceClosure resume) override {
-    base::Value chunkValue;
-
     bool encoded = !base::IsStringUTF8(chunk);
-    if (encoded) {
-      std::string encoded_string;
-      base::Base64Encode(chunk, &encoded_string);
-      chunkValue = base::Value(std::move(encoded_string));
-    } else {
-      chunkValue = base::Value(chunk);
-    }
-    base::Value id(stream_id_);
-    base::Value encodedValue(encoded);
-
-    bindings_->CallClientFunction("DevToolsAPI", "streamWrite", std::move(id),
-                                  std::move(chunkValue),
-                                  std::move(encodedValue));
+    bindings_->CallClientFunction(
+        "DevToolsAPI", "streamWrite", base::Value{stream_id_},
+        base::Value{encoded ? base::Base64Encode(chunk) : chunk},
+        base::Value{encoded});
     std::move(resume).Run();
   }