Add support for user defined "pool" to GN.

tools/gn/variables.h

Index: tools/gn/variables.h
diff --git a/tools/gn/variables.h b/tools/gn/variables.h
index 0aaa8e09a8dad08e59020cfff2fca7572b5a09a9..d4793f5bb621cf54ed3bc2828dd0d41c31e45ddc 100644
--- a/tools/gn/variables.h
+++ b/tools/gn/variables.h
@@ -167,6 +167,10 @@ extern const char kDeps[];
 extern const char kDeps_HelpShort[];
 extern const char kDeps_Help[];
 
+extern const char kDepth[];

[brettw, 2016/05/24 22:03:31]

This is never used or defined. I think it's OK not to have global definitions
for this since it's only used in one place. Just revert this file.

[sdefresne, 2016/05/26 15:38:37]

Ack.

+extern const char kDepth_HelpShort[];
+extern const char kDepth_Help[];
+
 extern const char kIncludeDirs[];
 extern const char kIncludeDirs_HelpShort[];
 extern const char kIncludeDirs_Help[];