Report CHECK/DCHECK to test launcher summary output.

This CL is continuation of previous one:
https://codereview.chromium.org/2606153003/

BUG=

Review-Url: https://codereview.chromium.org/2638763004
Cr-Commit-Position: refs/heads/master@{#465531}
diff --git a/base/strings/string_piece.h b/base/strings/string_piece.h
index 5333640f..08feb60 100644
--- a/base/strings/string_piece.h
+++ b/base/strings/string_piece.h
@@ -30,13 +30,10 @@
 #include "base/base_export.h"
 #include "base/logging.h"
 #include "base/strings/string16.h"
+#include "base/strings/string_piece_forward.h"
 
 namespace base {
 
-template <typename STRING_TYPE> class BasicStringPiece;
-typedef BasicStringPiece<std::string> StringPiece;
-typedef BasicStringPiece<string16> StringPiece16;
-
 // internal --------------------------------------------------------------------
 
 // Many of the StringPiece functions use different implementations for the