Write a phony target for the top-level directory of a create_bundle target.

tools/gn/bundle_data.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_BUNDLE_DATA_H_
 #define TOOLS_GN_BUNDLE_DATA_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 46 matching lines @@
 
   // Returns the list of outputs as SourceFile.
   void GetOutputsAsSourceFiles(
       const Settings* settings,
       SourceFiles* outputs_as_source) const;
 
   // Returns the path to the compiled asset catalog. Only valid if
   // asset_catalog_sources() is not empty.
   SourceFile GetCompiledAssetCatalogPath() const;
 
+  // Returns the path to the top-level directory of the bundle. This is
+  // based on root_dir(), but since that can be Bundle.app/Contents/ or
+  // any other subpath, this is just the most top-level directory (e.g.,
+  // just Bundle.app/).
+  //
+  // Note that this is a SourceFile instead of a SourceDir. This is because
+  // the output of a create_bundle rule is a single logical unit, even though
+  // it is really a directory containing many outputs. This allows other
+  // targets to treat the bundle as a single unit, rather than a collection
+  // of its contents.
+  SourceFile GetBundleRootDirOutput(const Settings* settings) const;
+
   // Returns the list of inputs for the compilation of the asset catalog.
   SourceFiles& asset_catalog_sources() { return asset_catalog_sources_; }
   const SourceFiles& asset_catalog_sources() const {
     return asset_catalog_sources_;
   }
 
   BundleFileRules& file_rules() { return file_rules_; }
   const BundleFileRules& file_rules() const { return file_rules_; }
 
   std::string& root_dir() { return root_dir_; }
@@ skipping 18 matching lines @@
 
   // All those values are subdirectories relative to root_build_dir, and apart
   // from root_dir, they are either equal to root_dir_ or subdirectories of it.
   std::string root_dir_;
   std::string resources_dir_;
   std::string executable_dir_;
   std::string plugins_dir_;
 };
 
 #endif  // TOOLS_GN_BUNDLE_DATA_H_