Fix code style violation in compiler/preprocessor

BUG=angle:650
TEST=no behavior change

Change-Id: Ib52f15f6471fc7897b66d11baee11216cf08158a
Reviewed-on: https://chromium-review.googlesource.com/199591
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Tested-by: Zhenyao Mo <zmo@chromium.org>
diff --git a/src/compiler/preprocessor/DiagnosticsBase.h b/src/compiler/preprocessor/DiagnosticsBase.h
index 2c8c539..a7587ed 100644
--- a/src/compiler/preprocessor/DiagnosticsBase.h
+++ b/src/compiler/preprocessor/DiagnosticsBase.h
@@ -72,15 +72,15 @@
 
     virtual ~Diagnostics();
 
-    void report(ID id, const SourceLocation& loc, const std::string& text);
+    void report(ID id, const SourceLocation &loc, const std::string &text);
 
   protected:
     Severity severity(ID id);
     std::string message(ID id);
 
     virtual void print(ID id,
-                       const SourceLocation& loc,
-                       const std::string& text) = 0;
+                       const SourceLocation &loc,
+                       const std::string &text) = 0;
 };
 
 }  // namespace pp