Wrap all preprocessor code in the angle namespace.

BUG=836820
BUG=801364

Change-Id: I08b6a2f9f12b689e09df6efd916c313e71e8a051
Reviewed-on: https://chromium-review.googlesource.com/1028581
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
diff --git a/src/compiler/preprocessor/DirectiveParser.cpp b/src/compiler/preprocessor/DirectiveParser.cpp
index f6c5763..0731a41 100644
--- a/src/compiler/preprocessor/DirectiveParser.cpp
+++ b/src/compiler/preprocessor/DirectiveParser.cpp
@@ -18,6 +18,9 @@
 #include "compiler/preprocessor/Token.h"
 #include "compiler/preprocessor/Tokenizer.h"
 
+namespace angle
+{
+
 namespace
 {
 enum DirectiveType
@@ -998,3 +1001,5 @@
 }
 
 }  // namespace pp
+
+}  // namespace angle