Fuchsia: Use new call to get thread CPU time

runtime/bin/thread_fuchsia.cc

Index: runtime/bin/thread_fuchsia.cc
diff --git a/runtime/bin/thread_fuchsia.cc b/runtime/bin/thread_fuchsia.cc
index fa5397ff131e138c50e7436be8be23242c9d1bf5..0e3408e7b68a390bdb5f9783cf0809575617276a 100644
--- a/runtime/bin/thread_fuchsia.cc
+++ b/runtime/bin/thread_fuchsia.cc
@@ -8,9 +8,11 @@
 #include "bin/thread.h"
 #include "bin/thread_fuchsia.h"
 
-#include <errno.h>         // NOLINT
-#include <sys/resource.h>  // NOLINT
-#include <sys/time.h>      // NOLINT
+#include <errno.h>             // NOLINT
+#include <magenta/syscalls.h>  // NOLINT
+#include <magenta/types.h>     // NOLINT
+#include <sys/resource.h>      // NOLINT
+#include <sys/time.h>          // NOLINT
 
 #include "platform/assert.h"
 #include "platform/utils.h"
@@ -166,7 +168,9 @@ bool Thread::Compare(ThreadId a, ThreadId b) {
 
 
 void Thread::GetThreadCpuUsage(ThreadId thread_id, int64_t* cpu_usage) {

[rmacnak, 2017/01/06 18:34:24]

bin::Thread::GetThreadCpuUsage is unused. We should remove it.

[zra, 2017/01/07 22:45:17]

Done.

-  UNIMPLEMENTED();
+  ASSERT(thread_id == GetCurrentThreadId());
+  ASSERT(cpu_usage != NULL);
+  *cpu_usage = mx_time_get(MX_CLOCK_THREAD) / kNanosecondsPerMicrosecond;
 }