Fully qualify path to cl.exe for ninja windows, and support *_wrapper from environment

pylib/gyp/generator/ninja.py

Index: pylib/gyp/generator/ninja.py
===================================================================
--- pylib/gyp/generator/ninja.py	(revision 1611)
+++ pylib/gyp/generator/ninja.py	(working copy)
@@ -370,6 +370,8 @@
                                                            generator_flags)
       arch = self.msvs_settings.GetArch(config_name)
       self.ninja.variable('arch', self.win_env[arch])
+      self.ninja.variable('cc', '$cl_' + arch)
+      self.ninja.variable('cxx', '$cl_' + arch)
 
     # Compute predepends for all rules.
     # actions_depends is the dependencies this target depends on before running
@@ -1370,8 +1372,10 @@
     cc = 'cl.exe'
     cxx = 'cl.exe'
     ld = 'link.exe'
-    gyp.msvs_emulation.GenerateEnvironmentFiles(
+    cl_paths = gyp.msvs_emulation.GenerateEnvironmentFiles(
         toplevel_build, generator_flags, OpenOutput)
+    for arch, path in cl_paths.iteritems():
+      master_ninja.variable('cl_' + arch, path)
     ld_host = '$ld'
   else:
     cc = 'gcc'
@@ -1430,7 +1434,6 @@
     master_ninja.variable('rc', 'rc.exe')
     master_ninja.variable('asm', 'ml.exe')
     master_ninja.variable('mt', 'mt.exe')
-    master_ninja.variable('use_dep_database', '1')

[Nico, 2013/04/16 23:02:59]

Was this ever used for anything? (I guess it was used in your fork, but not in
version we launched?)

   else:
     master_ninja.variable('ld', CommandWithWrapper('LINK', wrappers, ld))
     master_ninja.variable('ar', GetEnvironFallback(['AR_target', 'AR'], 'ar'))