Support Visual C++ PGO in Ninja generator

test/win/linker-flags/ltcg.gyp

Index: test/win/linker-flags/ltcg.gyp
===================================================================
--- test/win/linker-flags/ltcg.gyp	(revision 0)
+++ test/win/linker-flags/ltcg.gyp	(revision 0)
@@ -0,0 +1,42 @@
+# Copyright (c) 2013 Google Inc. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+{
+  'targets': [
+    {
+      'target_name': 'test_ltcg_off',
+      'type': 'executable',
+      'msvs_settings': {
+        'VCCLCompilerTool': {
+          'WholeProgramOptimization': 'false',
+        },
+        'VCLinkerTool': {
+          'LinkTimeCodeGeneration': '0',
+        },
+      },
+      'sources': [
+        'inline_test.h',
+        'inline_test.cc',
+        'inline_test_main.cc',
+      ],
+    },
+    {
+      'target_name': 'test_ltcg_on',
+      'type': 'executable',
+      'msvs_settings': {
+        'VCCLCompilerTool': {
+          'WholeProgramOptimization': 'true',  # /GL
+        },
+        'VCLinkerTool': {
+          'LinkTimeCodeGeneration': '1',       # /LTCG
+        },
+      },
+      'sources': [
+        'inline_test.h',
+        'inline_test.cc',
+        'inline_test_main.cc',
+      ],
+    },
+  ]
+}