base/allocator: Fix conditional build settings of mallinfo

mallinfo is not a POSIX API and OS_APPLE doesn't support mallinfo
nor define 'struct mallinfo'.  Also <malloc.h> is not available on
OS_APPLE.

Change-Id: Ibe6834c7840e0e01aa85106cc6de0cf1ecf0fcf7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2505691Reviewed-by: Benoit L <lizeb@chromium.org>
Reviewed-by: Will Harris <wfh@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822600}

base/allocator/allocator_shim_default_dispatch_to_partition_alloc.cc

@@ -14,7 +14,7 @@
 #include "base/no_destructor.h"
 #include "build/build_config.h"
 
-#if defined(OS_POSIX)
+#if defined(OS_POSIX) && !defined(OS_APPLE)
 #include <malloc.h>
 #endif
 
@@ -263,7 +263,8 @@ SHIM_ALWAYS_EXPORT int mallopt(int cmd, int value) __THROW {
 
 #endif  // !defined(OS_APPLE)
 
-#if defined(OS_POSIX)
+// mallinfo is not a POSIX API and OS_APPLE doesn't support it.
+#if defined(OS_POSIX) && !defined(OS_APPLE)
 SHIM_ALWAYS_EXPORT struct mallinfo mallinfo(void) __THROW {
   base::SimplePartitionStatsDumper allocator_dumper;
   Allocator()->DumpStats("malloc", true, &allocator_dumper);
@@ -287,6 +288,6 @@ SHIM_ALWAYS_EXPORT struct mallinfo mallinfo(void) __THROW {
 
   return info;
 }
-#endif  // defined(OS_POSIX)
+#endif  // defined(OS_POSIX) && !defined(OS_APPLE)
 
 }  // extern "C"

base/allocator/allocator_shim_default_dispatch_to_partition_alloc_unittest.cc

@@ -7,7 +7,7 @@
 #include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-#if defined(OS_POSIX)
+#if defined(OS_POSIX) && !defined(OS_APPLE)
 #include <malloc.h>
 #include <stdlib.h>
 #endif