Revert of Move JoinString to the base namespace

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 90c12a0785088aa2c54745fea44bde7c6c17309e..71dbd5641781397282be1e1ef9902fe616d2a107 100644
--- a/remoting/base/capabilities_unittest.cc
+++ b/remoting/base/capabilities_unittest.cc
@@ -67,7 +67,7 @@
         base::SPLIT_WANT_NONEMPTY);
     do {
       EXPECT_EQ(data[i].result,
-                HasCapability(base::JoinString(caps, " "), data[i].key));
+                HasCapability(JoinString(caps, " "), data[i].key));
     } while (std::next_permutation(caps.begin(), caps.end()));
   }
 }
@@ -98,8 +98,7 @@
         data[i].left, " ", base::KEEP_WHITESPACE, base::SPLIT_WANT_NONEMPTY);
     do {
       EXPECT_EQ(data[i].result,
-                IntersectCapabilities(base::JoinString(caps, " "),
-                                      data[i].right));
+                IntersectCapabilities(JoinString(caps, " "), data[i].right));
     } while (std::next_permutation(caps.begin(), caps.end()));
   }
 }