Fix performance-for-range-copy warnings

Bug: 30413223
Test: make with WITH_TIDY=1 DEFAULT_GLOBAL_TIDY_CHECKS=-*,performance*
Change-Id: Ie481e88025a7a1f3abde8ff63420d5ccd8577e52
diff --git a/tools/aapt2/ResourceParser.cpp b/tools/aapt2/ResourceParser.cpp
index 39ca80b..968376b 100644
--- a/tools/aapt2/ResourceParser.cpp
+++ b/tools/aapt2/ResourceParser.cpp
@@ -78,7 +78,7 @@
 
 static uint32_t ParseFormatAttribute(const StringPiece& str) {
   uint32_t mask = 0;
-  for (StringPiece part : util::Tokenize(str, '|')) {
+  for (const StringPiece& part : util::Tokenize(str, '|')) {
     StringPiece trimmed_part = util::TrimWhitespace(part);
     uint32_t type = ParseFormatType(trimmed_part);
     if (type == 0) {
diff --git a/tools/aapt2/ResourceUtils.cpp b/tools/aapt2/ResourceUtils.cpp
index 82d9e04..99420de 100644
--- a/tools/aapt2/ResourceUtils.cpp
+++ b/tools/aapt2/ResourceUtils.cpp
@@ -360,7 +360,7 @@
     return util::make_unique<BinaryPrimitive>(flags);
   }
 
-  for (StringPiece part : util::Tokenize(str, '|')) {
+  for (const StringPiece& part : util::Tokenize(str, '|')) {
     StringPiece trimmed_part = util::TrimWhitespace(part);
 
     bool flag_set = false;
diff --git a/tools/aapt2/cmd/Compile.cpp b/tools/aapt2/cmd/Compile.cpp
index 411ad74..0b43c5d 100644
--- a/tools/aapt2/cmd/Compile.cpp
+++ b/tools/aapt2/cmd/Compile.cpp
@@ -486,7 +486,7 @@
     }
 
     Printer r_txt_printer(&fout_text);
-    for (const auto res : xmlres->file.exported_symbols) {
+    for (const auto& res : xmlres->file.exported_symbols) {
       r_txt_printer.Print("default int id ");
       r_txt_printer.Println(res.name.entry);
     }
diff --git a/tools/aapt2/java/AnnotationProcessor.cpp b/tools/aapt2/java/AnnotationProcessor.cpp
index 8d91b00..a4610b2 100644
--- a/tools/aapt2/java/AnnotationProcessor.cpp
+++ b/tools/aapt2/java/AnnotationProcessor.cpp
@@ -113,7 +113,7 @@
 void AnnotationProcessor::Print(Printer* printer) const {
   if (has_comments_) {
     std::string result = comment_.str();
-    for (StringPiece line : util::Tokenize(result, '\n')) {
+    for (const StringPiece& line : util::Tokenize(result, '\n')) {
       printer->Println(line);
     }
     printer->Println(" */");
diff --git a/tools/aapt2/util/Files.cpp b/tools/aapt2/util/Files.cpp
index 5a8ff09..a407c22 100644
--- a/tools/aapt2/util/Files.cpp
+++ b/tools/aapt2/util/Files.cpp
@@ -165,7 +165,7 @@
 
 std::string PackageToPath(const StringPiece& package) {
   std::string out_path;
-  for (StringPiece part : util::Tokenize(package, '.')) {
+  for (const StringPiece& part : util::Tokenize(package, '.')) {
     AppendPath(&out_path, part);
   }
   return out_path;