s/size_t/std::size_t/g - for compatibility with other builds

For compatibility with the Google3 build system, use std::size_t instead
of gnu size_t.

Change-Id: Ie361de9c507119aa7db93d24b6e199547bd123af
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/internal/sys.cpp b/internal/sys.cpp
index f6a686e..b99a2f2 100644
--- a/internal/sys.cpp
+++ b/internal/sys.cpp
@@ -34,13 +34,13 @@
     return ::close(fd);
 }
 
-void* SysImpl::mmap(void* addr, size_t length, int prot, int flags, int fd,
+void* SysImpl::mmap(void* addr, std::size_t length, int prot, int flags, int fd,
                     off_t offset) const
 {
     return ::mmap(addr, length, prot, flags, fd, offset);
 }
 
-int SysImpl::munmap(void* addr, size_t length) const
+int SysImpl::munmap(void* addr, std::size_t length) const
 {
     return ::munmap(addr, length);
 }
diff --git a/internal/sys.hpp b/internal/sys.hpp
index 98221c3..98b6e5c 100644
--- a/internal/sys.hpp
+++ b/internal/sys.hpp
@@ -27,9 +27,9 @@
 
     virtual int open(const char* pathname, int flags) const = 0;
     virtual int close(int fd) const = 0;
-    virtual void* mmap(void* addr, size_t length, int prot, int flags, int fd,
-                       off_t offset) const = 0;
-    virtual int munmap(void* addr, size_t length) const = 0;
+    virtual void* mmap(void* addr, std::size_t length, int prot, int flags,
+                       int fd, off_t offset) const = 0;
+    virtual int munmap(void* addr, std::size_t length) const = 0;
     virtual int getpagesize() const = 0;
     virtual int ioctl(int fd, unsigned long request, void* param) const = 0;
     virtual int poll(struct pollfd* fds, nfds_t nfds, int timeout) const = 0;
@@ -45,9 +45,9 @@
   public:
     int open(const char* pathname, int flags) const override;
     int close(int fd) const override;
-    void* mmap(void* addr, size_t length, int prot, int flags, int fd,
+    void* mmap(void* addr, std::size_t length, int prot, int flags, int fd,
                off_t offset) const override;
-    int munmap(void* addr, size_t length) const override;
+    int munmap(void* addr, std::size_t length) const override;
     int getpagesize() const override;
     int ioctl(int fd, unsigned long request, void* param) const override;
     int poll(struct pollfd* fds, nfds_t nfds, int timeout) const override;