[GN] Add support for code signing to "create_bundle" targets.

tools/gn/ninja_create_bundle_target_writer.h

 // Copyright 2016 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_NINJA_CREATE_BUNDLE_TARGET_WRITER_H_
 #define TOOLS_GN_NINJA_CREATE_BUNDLE_TARGET_WRITER_H_
 
 #include "base/macros.h"
 #include "tools/gn/ninja_target_writer.h"
 
 // Writes a .ninja file for a bundle_data target type.
 class NinjaCreateBundleTargetWriter : public NinjaTargetWriter {
  public:
   NinjaCreateBundleTargetWriter(const Target* target, std::ostream& out);
   ~NinjaCreateBundleTargetWriter() override;
 
   void Run() override;
 
  private:
+  // Writes the Ninja rule for invoking the code signing script.
+  //
+  // Returns the name of the custom rule generated for the code signing step if
+  // defined, otherwise returns an empty string.
+  std::string WriteCodeSigningRuleDefinition();
+
+  // Writes the rule to copy files into the bundle.
+  //
+  // input_dep is a file expressing the shared dependencies. It will be a
+  // stamp file if there is more than one.
+  void WriteCopyBundleDataRules(const OutputFile& input_dep,
+                                std::vector<OutputFile>* output_files);
+
+  // Writes the rule to compile assets catalogs.
+  //
+  // input_dep is a file expressing the shared dependencies. It will be a
+  // stamp file if there is more than one.
+  void WriteCompileAssetsCatalogRule(const OutputFile& input_dep,
+                                     std::vector<OutputFile>* output_files);
+
+  // Writes the code signing rule (if a script is defined).
+  //
+  // input_dep is a file expressing the shared dependencies. It will be a
+  // stamp file if there is more than one. As the code signing may include
+  // a manifest of the file, this will depends on all files in output_files
+  // too.
+  void WriteCodeSigningRules(const std::string& code_signing_rule_name,
+                             const OutputFile& input_dep,
+                             std::vector<OutputFile>* output_files);
+
+  // Writes the stamp file for the code signing input dependencies.
+  OutputFile WriteCodeSigningInputDepsStamp(
+      const OutputFile& input_dep,
+      std::vector<OutputFile>* output_files);
+
   DISALLOW_COPY_AND_ASSIGN(NinjaCreateBundleTargetWriter);
 };
 
 #endif  // TOOLS_GN_NINJA_CREATE_BUNDLE_TARGET_WRITER_H_