Add iOS support to common.gypi

build/build_config.h

Index: build/build_config.h
diff --git a/build/build_config.h b/build/build_config.h
index 731e7763f732256e568757297459e32f0c54f7b9..08e35b8976f6c6945c39456b5f8f7be6b47aaae9 100644
--- a/build/build_config.h
+++ b/build/build_config.h
@@ -14,9 +14,16 @@
 #ifndef BUILD_BUILD_CONFIG_H_
 #define BUILD_BUILD_CONFIG_H_
 
+#if defined(__APPLE__)
+#include <TargetConditionals.h>
+#endif
+
 // A set of macros to use for platform detection.
 #if defined(__APPLE__)
 #define OS_MACOSX 1
+#if defined(TARGET_OS_IPHONE)
+#define OS_IOS 1
+#endif  // defined(TARGET_OS_IPHONE)
 #elif defined(ANDROID)
 #define OS_ANDROID 1
 #elif defined(__native_client__)
@@ -99,7 +106,6 @@
 #define ARCH_CPU_ARMEL 1
 #define ARCH_CPU_32_BITS 1
 #define ARCH_CPU_LITTLE_ENDIAN 1
-#define WCHAR_T_IS_UNSIGNED 1
 #elif defined(__pnacl__)
 #define ARCH_CPU_32_BITS 1
 #elif defined(__MIPSEL__)
@@ -107,7 +113,6 @@
 #define ARCH_CPU_MIPSEL 1
 #define ARCH_CPU_32_BITS 1
 #define ARCH_CPU_LITTLE_ENDIAN 1
-#define WCHAR_T_IS_UNSIGNED 0
 #else
 #error Please add support for your architecture in build/build_config.h
 #endif
@@ -131,6 +136,12 @@
 #error Please add support for your compiler in build/build_config.h
 #endif
 
+#if defined(__ARMEL__) && !defined(OS_IOS)
+#define WCHAR_T_IS_UNSIGNED 1
+#elif defined(__MIPSEL__)
+#define WCHAR_T_IS_UNSIGNED 0
+#endif
+
 #if defined(OS_CHROMEOS)
 // Single define to trigger whether CrOS fonts have BCI on.
 // In that case font sizes/deltas should be adjusted.