Integrate double-conversion into build-process.

runtime/third_party/double-conversion/src/double-conversion.gypi

Index: runtime/third_party/double-conversion/src/double-conversion.gypi
diff --git a/runtime/third_party/double-conversion/src/double-conversion.gypi b/runtime/third_party/double-conversion/src/double-conversion.gypi
new file mode 100644
index 0000000000000000000000000000000000000000..936de9228413974bbd7ac478371c21a8ea4b4790
--- /dev/null
+++ b/runtime/third_party/double-conversion/src/double-conversion.gypi
@@ -0,0 +1,47 @@
+# Copyright 2010 Google Inc. All Rights Reserved.
+
+{
+  # Needed for compilation with g++ 4.5.
+  'conditions': [
+    [ 'OS=="linux"', { 'variables' : {
+      'common_gcc_warning_flags': [ '-Wno-conversion-null', ], }, } ],
+    [ 'OS=="mac"', { 'variables' : {
+      'common_gcc_warning_flags': [ '-w', ], }, } ],
+  ],
+  'includes': [
+    '../../../../tools/gyp/xcode.gypi',
+    '../../../../tools/gyp/configurations.gypi',
+    '../../../../tools/gyp/source_filter.gypi',
+  ],
+  'targets': [
+    {
+      'target_name': 'libdouble_conversion',
+      'type': 'static_library',
+      'dependencies': [
+      ],
+      'include_dirs': [
+        '.',
+      ],
+      'sources': [
+        'bignum.cc',
+        'bignum.h',
+        'bignum-dtoa.cc',
+        'bignum-dtoa.h',
+        'cached-powers.cc',
+        'cached-powers.h',
+        'diy-fp.cc',
+        'diy-fp.h',
+        'double.h',
+        'double-conversion.cc',
+        'double-conversion.h',
+        'fast-dtoa.cc',
+        'fast-dtoa.h',
+        'fixed-dtoa.cc',
+        'fixed-dtoa.h',
+        'strtod.cc',
+        'strtod.h',
+        'utils.h',
+      ],
+    },
+  ],
+}