Change uses of base::JoinString to pass StringPieces where possible.

remoting/base/capabilities.cc

Index: remoting/base/capabilities.cc
diff --git a/remoting/base/capabilities.cc b/remoting/base/capabilities.cc
index 4903aedfe5fab84b1cb3086500d6bf2dc67f738e..490bb5abee5b4aebfaddf59c79074d7a4407c2b9 100644
--- a/remoting/base/capabilities.cc
+++ b/remoting/base/capabilities.cc
@@ -8,6 +8,7 @@
 #include <vector>
 
 #include "base/stl_util.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 
@@ -22,19 +23,18 @@ bool HasCapability(const std::string& capabilities, const std::string& key) {
 
 std::string IntersectCapabilities(const std::string& client_capabilities,
                                   const std::string& host_capabilities) {
-  std::vector<std::string> client_caps = base::SplitString(
-      client_capabilities, " ", base::KEEP_WHITESPACE,
-      base::SPLIT_WANT_NONEMPTY);
+  std::vector<base::StringPiece> client_caps =
+      base::SplitStringPiece(client_capabilities, " ", base::KEEP_WHITESPACE,
+                             base::SPLIT_WANT_NONEMPTY);
   std::sort(client_caps.begin(), client_caps.end());
 
-  std::vector<std::string> host_caps = base::SplitString(
-        host_capabilities, " ", base::KEEP_WHITESPACE,
-        base::SPLIT_WANT_NONEMPTY);
+  std::vector<base::StringPiece> host_caps = base::SplitStringPiece(
+      host_capabilities, " ", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
   std::sort(host_caps.begin(), host_caps.end());
 
-  std::vector<std::string> result =
-      base::STLSetIntersection<std::vector<std::string> >(
-          client_caps, host_caps);
+  std::vector<base::StringPiece> result =
+      base::STLSetIntersection<std::vector<base::StringPiece>>(client_caps,
+                                                               host_caps);
 
   return base::JoinString(result, " ");
 }