Move CommandLine to base namespace.

tools/gn/setup.h

Index: tools/gn/setup.h
diff --git a/tools/gn/setup.h b/tools/gn/setup.h
index 4d8d29baa16e330b731615d45b83b67ad8d3dfd6..0a5c3427730419300d0747587c69f3143c838ad2 100644
--- a/tools/gn/setup.h
+++ b/tools/gn/setup.h
@@ -20,10 +20,13 @@
 #include "tools/gn/token.h"
 #include "tools/gn/toolchain.h"
 
-class CommandLine;
 class InputFile;
 class ParseNode;
 
+namespace base {
+class CommandLine;
+}
+
 extern const char kDotfile_Help[];
 
 // Base class for code shared between Setup and DependentSetup.
@@ -95,10 +98,10 @@ class Setup : public CommonSetup {
 
  private:
   // Fills build arguments. Returns true on success.
-  bool FillArguments(const CommandLine& cmdline);
+  bool FillArguments(const base::CommandLine& cmdline);
 
   // Fills the root directory into the settings. Returns true on success.
-  bool FillSourceDir(const CommandLine& cmdline);
+  bool FillSourceDir(const base::CommandLine& cmdline);
 
   // Fills the build directory given the value the user has specified.
   // Must happen after FillSourceDir so we can resolve source-relative
@@ -112,7 +115,7 @@ class Setup : public CommonSetup {
   // Run config file.
   bool RunConfigFile();
 
-  bool FillOtherConfig(const CommandLine& cmdline);
+  bool FillOtherConfig(const base::CommandLine& cmdline);
 
   Scheduler scheduler_;