preprocessor: Miscellaneous cleanups

- Use full header paths in includes
- Use ASSERT instead of assert
- Use angle::NonCopyable instead of PP_DISALLOW_COPY_AND_ASSIGN
- Use range-for in a couple places
- Remove pp_utils.h

BUG=angleproject:1522

Change-Id: If107fef89e8465bca65cf664926d1051c5d1e232
Reviewed-on: https://chromium-review.googlesource.com/387212
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
diff --git a/src/compiler/preprocessor/Lexer.h b/src/compiler/preprocessor/Lexer.h
index 990dc5e..775bc0a 100644
--- a/src/compiler/preprocessor/Lexer.h
+++ b/src/compiler/preprocessor/Lexer.h
@@ -7,12 +7,14 @@
 #ifndef COMPILER_PREPROCESSOR_LEXER_H_
 #define COMPILER_PREPROCESSOR_LEXER_H_
 
+#include "common/angleutils.h"
+
 namespace pp
 {
 
 struct Token;
 
-class Lexer
+class Lexer : angle::NonCopyable
 {
   public:
     virtual ~Lexer();