Stop using sys/resource.h and rusage.

They're legacy POSIX interfaces that don't make sense on Fuchsia.

Change-Id: I77c5c33bbf658c3c391b5d1a7e9c16c3d908ebd8
diff --git a/src/benchmark.cc b/src/benchmark.cc
index 95f6a25..ae099b9 100644
--- a/src/benchmark.cc
+++ b/src/benchmark.cc
@@ -17,7 +17,9 @@
 #include "internal_macros.h"
 
 #ifndef BENCHMARK_OS_WINDOWS
+#ifndef __Fuchsia__
 #include <sys/resource.h>
+#endif
 #include <sys/time.h>
 #include <unistd.h>
 #endif
diff --git a/src/benchmark_register.cc b/src/benchmark_register.cc
index 4e580d8..14ee163 100644
--- a/src/benchmark_register.cc
+++ b/src/benchmark_register.cc
@@ -17,7 +17,9 @@
 #include "internal_macros.h"
 
 #ifndef BENCHMARK_OS_WINDOWS
+#ifndef __Fuchsia__
 #include <sys/resource.h>
+#endif
 #include <sys/time.h>
 #include <unistd.h>
 #endif
diff --git a/src/sysinfo.cc b/src/sysinfo.cc
index dd1e663..db25d33 100644
--- a/src/sysinfo.cc
+++ b/src/sysinfo.cc
@@ -21,7 +21,9 @@
 #include <Windows.h>
 #else
 #include <fcntl.h>
+#ifndef __Fuchsia__
 #include <sys/resource.h>
+#endif
 #include <sys/time.h>
 #include <sys/types.h>  // this header must be included before 'sys/sysctl.h' to avoid compilation error on FreeBSD
 #include <unistd.h>
diff --git a/src/timers.cc b/src/timers.cc
index fadc08f..d360843 100644
--- a/src/timers.cc
+++ b/src/timers.cc
@@ -21,7 +21,9 @@
 #include <Windows.h>
 #else
 #include <fcntl.h>
+#ifndef __Fuchsia__
 #include <sys/resource.h>
+#endif
 #include <sys/time.h>
 #include <sys/types.h>  // this header must be included before 'sys/sysctl.h' to avoid compilation error on FreeBSD
 #include <unistd.h>
@@ -70,7 +72,7 @@
           static_cast<double>(user.QuadPart)) *
          1e-7;
 }
-#else
+#elif !defined(__Fuchsia__)
 double MakeTime(struct rusage const& ru) {
   return (static_cast<double>(ru.ru_utime.tv_sec) +
           static_cast<double>(ru.ru_utime.tv_usec) * 1e-6 +