Mojo: COMPILE_ASSERT -> static_assert in mojo/system and mojo/embedder.

mojo/embedder/simple_platform_shared_buffer_posix.cc

Index: mojo/embedder/simple_platform_shared_buffer_posix.cc
diff --git a/mojo/embedder/simple_platform_shared_buffer_posix.cc b/mojo/embedder/simple_platform_shared_buffer_posix.cc
index 55ec73c63e2b47d375024da547e4376191e7763c..9a111735eef9b97512c75373512b88b64fb8af1a 100644
--- a/mojo/embedder/simple_platform_shared_buffer_posix.cc
+++ b/mojo/embedder/simple_platform_shared_buffer_posix.cc
@@ -25,8 +25,8 @@
 
 // We assume that |size_t| and |off_t| (type for |ftruncate()|) fits in a
 // |uint64_t|.
-COMPILE_ASSERT(sizeof(size_t) <= sizeof(uint64_t), size_t_too_big);
-COMPILE_ASSERT(sizeof(off_t) <= sizeof(uint64_t), off_t_too_big);
+static_assert(sizeof(size_t) <= sizeof(uint64_t), "size_t too big");
+static_assert(sizeof(off_t) <= sizeof(uint64_t), "off_t too big");
 
 namespace mojo {
 namespace embedder {