Don't propagate deps across actions in GN.

tools/gn/target.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_TARGET_H_
 #define TOOLS_GN_TARGET_H_
 
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 50 matching lines @@
   Target* AsTarget() override;
   const Target* AsTarget() const override;
   bool OnResolved(Err* err) override;
 
   OutputType output_type() const { return output_type_; }
   void set_output_type(OutputType t) { output_type_ = t; }
 
   // Can be linked into other targets.
   bool IsLinkable() const;
 
-  // Can have dependencies linked in.
+  // True if the target links dependencies rather than propogated up the graph.
+  // This is also true of action and copy steps even though they don't link
+  // dependencies, because they also don't propogate libraries up.
   bool IsFinal() const;
 
   // Will be the empty string to use the target label as the output name.
   // See GetComputedOutputName().
   const std::string& output_name() const { return output_name_; }
   void set_output_name(const std::string& name) { output_name_ = name; }
 
   // Returns the output name for this target, which is the output_name if
   // specified, or the target label if not. If the flag is set, it will also
   // include any output prefix specified on the tool (often "lib" on Linux).
@@ skipping 237 matching lines @@
 
   // Output files. Empty until the target is resolved.
   std::vector<OutputFile> computed_outputs_;
   OutputFile link_output_file_;
   OutputFile dependency_output_file_;
 
   DISALLOW_COPY_AND_ASSIGN(Target);
 };
 
 #endif  // TOOLS_GN_TARGET_H_