Support Android in MallocHook for mmap, munmap and mremap.

third_party/tcmalloc/chromium/src/base/linux_syscall_support.h

Index: third_party/tcmalloc/chromium/src/base/linux_syscall_support.h
diff --git a/third_party/tcmalloc/chromium/src/base/linux_syscall_support.h b/third_party/tcmalloc/chromium/src/base/linux_syscall_support.h
index d768471b33fee93b6fa7ecda7bdbd87c497d0d25..bdbc4b7e3bbfc023f9ea83c34cf59974ac09a068 100644
--- a/third_party/tcmalloc/chromium/src/base/linux_syscall_support.h
+++ b/third_party/tcmalloc/chromium/src/base/linux_syscall_support.h
@@ -155,7 +155,12 @@ extern "C" {
 #include <sys/resource.h>
 #include <sys/time.h>
 #include <sys/types.h>
+#if defined(__ANDROID__)
+#include <sys/syscall.h>
+#include <sys/linux-syscalls.h>
+#else
 #include <syscall.h>
+#endif
 #include <unistd.h>
 #include <linux/unistd.h>
 #include <endian.h>
@@ -471,6 +476,11 @@ struct kernel_stat {
 };
 #endif
 
+// ulong is not defined in Android while used to define __llseek.
+#if defined(__ANDROID__)
+typedef unsigned long int ulong;
+#endif
+
 
 /* Definitions missing from the standard header files                        */
 #ifndef O_DIRECTORY
@@ -1961,7 +1971,8 @@ struct kernel_stat {
       return LSS_NAME(wait4)(pid, status, options, 0);
     }
    #endif
-  #if defined(__i386__) || defined(__x86_64__) || defined(__arm__)
+  #if (defined(__i386__) || defined(__x86_64__) || defined(__arm__)) && \
+      !defined(__ANDROID__)
     LSS_INLINE _syscall4(int, openat, int, d, const char *, p, int, f, int, m)
   #endif
   LSS_INLINE int LSS_NAME(sigemptyset)(struct kernel_sigset_t *set) {