base: Use more specific CHECK macros for comparisons.

base/memory/shared_memory_posix.cc

Index: base/memory/shared_memory_posix.cc
diff --git a/base/memory/shared_memory_posix.cc b/base/memory/shared_memory_posix.cc
index fd26ad19ffbe1e3268d9b4165dd3591b4b0f6042..f8efa42c437e8f753f84f7b4c7e9fb0896db9739 100644
--- a/base/memory/shared_memory_posix.cc
+++ b/base/memory/shared_memory_posix.cc
@@ -453,7 +453,7 @@ bool SharedMemory::ShareToProcessCommon(ProcessHandle process,
     case SHARE_READONLY:
       // We could imagine re-opening the file from /dev/fd, but that can't make
       // it readonly on Mac: https://codereview.chromium.org/27265002/#msg10
-      CHECK(readonly_mapped_file_ >= 0);
+      CHECK_GE(readonly_mapped_file_, 0);
       handle_to_dup = readonly_mapped_file_;
       break;
   }