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 +1,73 @@
+# 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_default',
+      'type': 'executable',
+      'variables': {
+        'LinkTimeCodeGenerationOptionDefault': '0',
+      },
+      'msvs_settings': {
+        'VCLinkerTool': {
+          'LinkTimeCodeGeneration': '<(LinkTimeCodeGenerationOptionDefault)',
+        },
+      },
+      'sources': ['hello.cc'],
+    },
+    {
+      'target_name': 'test_ltcg_use',
+      'type': 'executable',
+      'variables': {
+        'LinkTimeCodeGenerationOptionUse': '1',
+      },
+      'msvs_settings': {
+        'VCLinkerTool': {
+          'LinkTimeCodeGeneration': '<(LinkTimeCodeGenerationOptionUse)',
+        },
+      },
+      'sources': ['hello.cc'],
+    },
+    {
+      'target_name': 'test_ltcg_instrument',
+      'type': 'executable',
+      'variables': {
+        'LinkTimeCodeGenerationOptionInstrument': '2',
+      },
+      'msvs_settings': {
+        'VCLinkerTool': {
+          'LinkTimeCodeGeneration': '<(LinkTimeCodeGenerationOptionInstrument)',
+        },
+      },
+      'sources': ['hello.cc'],
+    },
+    {
+      'target_name': 'test_ltcg_optimize',
+      'type': 'executable',
+      'variables': {
+        'LinkTimeCodeGenerationOptionOptimize': '3',
+      },
+      'msvs_settings': {
+        'VCLinkerTool': {
+          'LinkTimeCodeGeneration': '<(LinkTimeCodeGenerationOptionOptimize)',
+        },
+      },
+      'sources': ['hello.cc'],
+    },
+    {
+      'target_name': 'test_ltcg_update',
+      'type': 'executable',
+      'variables': {
+        'LinkTimeCodeGenerationOptionUpdate': '4',
+      },
+      'msvs_settings': {
+        'VCLinkerTool': {
+          'LinkTimeCodeGeneration': '<(LinkTimeCodeGenerationOptionUpdate)',
+        },
+      },
+      'sources': ['hello.cc'],
+    },
+  ]
+}