Honor $CC/$CC_host and friends in make generator.

pylib/gyp/generator/ninja.py

Index: pylib/gyp/generator/ninja.py
diff --git a/pylib/gyp/generator/ninja.py b/pylib/gyp/generator/ninja.py
index 7c1f50c4365d6216159d16838475a0027208da10..217e99cd2a5edd9e78508a192f68838e11fa4b96 100644
--- a/pylib/gyp/generator/ninja.py
+++ b/pylib/gyp/generator/ninja.py
@@ -1196,7 +1196,6 @@ def CalculateVariables(default_variables, params):
   """Calculate additional variables for use in the build (called by gyp)."""
   global generator_additional_non_configuration_keys
   global generator_additional_path_sections
-  cc_target = os.environ.get('CC.target', os.environ.get('CC', 'cc'))
   flavor = gyp.common.GetFlavor(params)
   if flavor == 'mac':
     default_variables.setdefault('OS', 'mac')
@@ -1475,14 +1474,17 @@ def GenerateOutputForConfig(target_list, target_dicts, data, params,
                       restat=True)
     # Note that ldflags goes at the end so that it has the option of
     # overriding default settings earlier in the command line.
+    command = ('%s gyp-win-tool link-wrapper $arch '
+              '$ld /nologo /OUT:$out /PDB:$out.pdb @$out.rsp' %
+              sys.executable)
+    if not os.environ.get('LD_target'):
+      command += (' && %s gyp-win-tool manifest-wrapper $arch '
+                 '$mt -nologo -manifest $manifests -out:$out.manifest' %
+                 sys.executable)
     master_ninja.rule(
         'link',
         description='LINK $out',
-        command=('%s gyp-win-tool link-wrapper $arch '
-                 '$ld /nologo /OUT:$out /PDB:$out.pdb @$out.rsp && '
-                 '%s gyp-win-tool manifest-wrapper $arch '
-                 '$mt -nologo -manifest $manifests -out:$out.manifest' %
-                 (sys.executable, sys.executable)),
+        command=command,
         rspfile='$out.rsp',
         rspfile_content='$in_newline $libs $ldflags')
   else: