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

remoting/base/capabilities_unittest.cc

Index: remoting/base/capabilities_unittest.cc
diff --git a/remoting/base/capabilities_unittest.cc b/remoting/base/capabilities_unittest.cc
index 8caf0112f11d9e761be478eb4a8b371de4937221..e88a58062578e44fd595dea235de181952af65dd 100644
--- a/remoting/base/capabilities_unittest.cc
+++ b/remoting/base/capabilities_unittest.cc
@@ -8,6 +8,7 @@
 #include <vector>
 
 #include "base/macros.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "remoting/base/capabilities.h"
@@ -65,9 +66,9 @@ TEST(CapabilitiesTest, HasCapability) {
   // Verify that HasCapability(|capabilities|, |key|) returns |result|.
   // |result|.
   for (size_t i = 0; i < arraysize(data); ++i) {
-    std::vector<std::string> caps = base::SplitString(
-        data[i].capabilities, " ", base::KEEP_WHITESPACE,
-        base::SPLIT_WANT_NONEMPTY);
+    std::vector<base::StringPiece> caps =
+        base::SplitStringPiece(data[i].capabilities, " ", base::KEEP_WHITESPACE,
+                               base::SPLIT_WANT_NONEMPTY);
     do {
       EXPECT_EQ(data[i].result,
                 HasCapability(base::JoinString(caps, " "), data[i].key));
@@ -97,7 +98,7 @@ TEST(CapabilitiesTest, Intersect) {
   // Verify that intersection of |right| with all permutations of |left| yields
   // |result|.
   for (size_t i = 0; i < arraysize(data); ++i) {
-    std::vector<std::string> caps = base::SplitString(
+    std::vector<base::StringPiece> caps = base::SplitStringPiece(
         data[i].left, " ", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
     do {
       EXPECT_EQ(data[i].result,