Fix ninja build with clang=1.

build/standalone.gypi

Index: build/standalone.gypi
diff --git a/build/standalone.gypi b/build/standalone.gypi
index 0e36b0e5f522bd77b2d863063cc114560179fa6c..15e856c4fab9abaf123196b55c59d9218e61d594 100644
--- a/build/standalone.gypi
+++ b/build/standalone.gypi
@@ -33,7 +33,7 @@
   'includes': ['toolchain.gypi'],
   'variables': {
     'component%': 'static_library',
-    'make_clang_dir%': '../third_party/llvm-build/Release+Asserts',
+    'clang_dir%': 'third_party/llvm-build/Release+Asserts',
     'clang_xcode%': 0,
     'visibility%': 'hidden',
     'v8_enable_backtrace%': 0,
@@ -487,10 +487,19 @@
       },  # target_defaults
     }],  # OS=="mac"
     ['clang==1 and ((OS!="mac" and OS!="ios") or clang_xcode==0) '
-        'and OS!="win"', {
+        'and OS!="win" and "<(GENERATOR)"=="make"', {
       'make_global_settings': [
-        ['CC', '<(make_clang_dir)/bin/clang'],
-        ['CXX', '<(make_clang_dir)/bin/clang++'],
+        ['CC', '../<(clang_dir)/bin/clang'],
+        ['CXX', '../<(clang_dir)/bin/clang++'],
+        ['CC.host', '$(CC)'],
+        ['CXX.host', '$(CXX)'],
+      ],
+    }],
+    ['clang==1 and ((OS!="mac" and OS!="ios") or clang_xcode==0) '
+        'and OS!="win" and "<(GENERATOR)"=="ninja"', {
+      'make_global_settings': [
+        ['CC', '<(clang_dir)/bin/clang'],
+        ['CXX', '<(clang_dir)/bin/clang++'],
         ['CC.host', '$(CC)'],
         ['CXX.host', '$(CXX)'],
       ],
@@ -498,7 +507,7 @@
     ['clang==1 and OS=="win"', {
       'make_global_settings': [
         # On Windows, gyp's ninja generator only looks at CC.
-        ['CC', '<(make_clang_dir)/bin/clang-cl'],
+        ['CC', '../<(clang_dir)/bin/clang-cl'],
       ],
     }],
     # TODO(yyanagisawa): supports GENERATOR==make