Implement `gn analyze`.

tools/gn/commands.h

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef TOOLS_GN_COMMANDS_H_
 #define TOOLS_GN_COMMANDS_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 11 matching lines @@
 class SourceFile;
 class Target;
 class Toolchain;
 
 // Each "Run" command returns the value we should return from main().
 
 namespace commands {
 
 typedef int (*CommandRunner)(const std::vector<std::string>&);
 
+extern const char kAnalyze[];
+extern const char kAnalyze_HelpShort[];
+extern const char kAnalyze_Help[];
+int RunAnalyze(const std::vector<std::string>& args);
+
 extern const char kArgs[];
 extern const char kArgs_HelpShort[];
 extern const char kArgs_Help[];
 int RunArgs(const std::vector<std::string>& args);
 
 extern const char kCheck[];
 extern const char kCheck_HelpShort[];
 extern const char kCheck_Help[];
 int RunCheck(const std::vector<std::string>& args);
 
@@ skipping 145 matching lines @@
                              const std::set<const Target*>& targets);
 void FilterAndPrintTargetSet(const std::set<const Target*>& targets,
                              base::ListValue* out);
 
 // Extra help from command_check.cc
 extern const char kNoGnCheck_Help[];
 
 }  // namespace commands
 
 #endif  // TOOLS_GN_COMMANDS_H_