Pass base::StringPiece by value, not reference, in //net

This is the result of

  git grep -l 'const base::StringPiece&' | \
    xargs sed -i -e 's/const base::StringPiece&/base::StringPiece/g'

plus one manual fixup in pem.cc because that file had a using
declaration. Per the header, it should be passed by value but a lot of
this code was written to older expectations.

Change-Id: I9e24b805114805aae2e907b6081359b486b576bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3971168
Reviewed-by: Adam Rice <[email protected]>
Auto-Submit: David Benjamin <[email protected]>
Commit-Queue: Adam Rice <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1062739}
diff --git a/net/server/web_socket_encoder.cc b/net/server/web_socket_encoder.cc
index ed8179d..812ab737 100644
--- a/net/server/web_socket_encoder.cc
+++ b/net/server/web_socket_encoder.cc
@@ -41,7 +41,7 @@
 const size_t kEightBytePayloadLengthField = 127;
 const size_t kMaskingKeyWidthInBytes = 4;
 
-WebSocket::ParseResult DecodeFrameHybi17(const base::StringPiece& frame,
+WebSocket::ParseResult DecodeFrameHybi17(base::StringPiece frame,
                                          bool client_frame,
                                          int* bytes_consumed,
                                          std::string* output,
@@ -293,10 +293,9 @@
 
 WebSocketEncoder::~WebSocketEncoder() = default;
 
-WebSocket::ParseResult WebSocketEncoder::DecodeFrame(
-    const base::StringPiece& frame,
-    int* bytes_consumed,
-    std::string* output) {
+WebSocket::ParseResult WebSocketEncoder::DecodeFrame(base::StringPiece frame,
+                                                     int* bytes_consumed,
+                                                     std::string* output) {
   bool compressed;
   std::string current_output;
   WebSocket::ParseResult result = DecodeFrameHybi17(