Remove GN GYP generator.

tools/gn/variables.cc

Index: tools/gn/variables.cc
diff --git a/tools/gn/variables.cc b/tools/gn/variables.cc
index 8fac8406221360e62c0f3ef28404d70e3fc00d6f..be75593d6eb337e83b6b812b916d7f009c72c3b6 100644
--- a/tools/gn/variables.cc
+++ b/tools/gn/variables.cc
@@ -466,24 +466,6 @@ const char kDirectDependentConfigs_Help[] =
     "\n"
     "  See also \"all_dependent_configs\".\n";
 
-const char kExternal[] = "external";
-const char kExternal_HelpShort[] =
-    "external: [boolean] Declares a target as externally generated.";
-const char kExternal_Help[] =
-    "external: Declares a target as externally generated.\n"
-    "\n"
-    "  External targets are treated like normal targets as far as dependent\n"
-    "  targets are concerned, but do not actually have their .ninja file\n"
-    "  written to disk. This allows them to be generated by an external\n"
-    "  program (e.g. GYP).\n"
-    "\n"
-    "  See also \"gn help gyp\".\n"
-    "\n"
-    "Example:\n"
-    "  static_library(\"foo\") {\n"
-    "    external = true\n"
-    "  }\n";
-
 const char kForwardDependentConfigsFrom[] = "forward_dependent_configs_from";
 const char kForwardDependentConfigsFrom_HelpShort[] =
     "forward_dependent_configs_from: [label list] Forward dependent's configs.";
@@ -523,31 +505,6 @@ const char kForwardDependentConfigsFrom_Help[] =
     "      forward_dependent_configs_from = deps\n"
     "    }\n";
 
-const char kGypFile[] = "gyp_file";
-const char kGypFile_HelpShort[] =
-    "gyp_file: [file name] Name of GYP file to write to in GYP mode.";
-const char kGypFile_Help[] =
-    "gyp_file: Name of GYP file to write to in GYP mode.\n"
-    "\n"
-    "  See \"gn help gyp\" for an overview of how this works.\n"
-    "\n"
-    "  Tip: If all targets in a given BUILD.gn file should go in the same\n"
-    "  GYP file, just put gyp_file = \"foo\" at the top of the file and\n"
-    "  the variable will be in scope for all targets.\n";
-
-const char kGypHeader[] = "gyp_header";
-const char kGypHeader_HelpShort[] =
-    "gyp_header: [string] Extra stuff to prepend to GYP files.";
-const char kGypHeader_Help[] =
-    "gyp_header: Extra stuff to prepend to GYP files.\n"
-    "\n"
-    "  A Python dictionary string. This will be inserted after the initial\n"
-    "  \"{\" in the GYP file. It is expected this is used to define the\n"
-    "  make_global_settings.\n"
-    "\n"
-    "  This string should end in a comma to keep the python dictionary syntax\n"
-    "  valid when everything is concatenated.\n";
-
 const char kHardDep[] = "hard_dep";
 const char kHardDep_HelpShort[] =
     "hard_dep: [boolean] Indicates a target should be built before dependees.";
@@ -837,10 +794,7 @@ const VariableInfoMap& GetTargetVariables() {
     INSERT_VARIABLE(Depfile)
     INSERT_VARIABLE(Deps)
     INSERT_VARIABLE(DirectDependentConfigs)
-    INSERT_VARIABLE(External)
     INSERT_VARIABLE(ForwardDependentConfigsFrom)
-    INSERT_VARIABLE(GypFile)
-    INSERT_VARIABLE(GypHeader)
     INSERT_VARIABLE(HardDep)
     INSERT_VARIABLE(IncludeDirs)
     INSERT_VARIABLE(Ldflags)