Add big-endian defines into base/build/build_config.h

Forgot to add into https://weave-review.googlesource.com/#/c/1632/

BUG=25017606

Change-Id: I146b5e540e9876eb44718e23bcda047806a80116
Reviewed-on: https://weave-review.googlesource.com/1652
Reviewed-by: Vitaly Buka <vitalybuka@google.com>

third_party/chromium/base/build/build_config.h

diff --git a/third_party/chromium/base/build/build_config.h b/third_party/chromium/base/build/build_config.h
index 904965a..347a636 100644
--- a/third_party/chromium/base/build/build_config.h
+++ b/third_party/chromium/base/build/build_config.h
@@ -147,6 +147,16 @@
 #define ARCH_CPU_32_BITS 1
 #define ARCH_CPU_LITTLE_ENDIAN 1
 #endif
+#elif defined(__mips__)
+#if defined(__LP64__)
+#define ARCH_CPU_MIPS64_FAMILY 1
+#define ARCH_CPU_64_BITS 1
+#define ARCH_CPU_BIG_ENDIAN 1
+#else
+#define ARCH_CPU_MIPS_FAMILY 1
+#define ARCH_CPU_32_BITS 1
+#define ARCH_CPU_BIG_ENDIAN 1
+#endif
 #else
 #error Please add support for your architecture in build/build_config.h
 #endif