Revert of SkTime::GetNSecs() (patchset #11 id:200001 of https://codereview.chromium.org/1422513003/ )

Reason for revert:
Times don't look like they make sense on Windows.

Original issue's description:
> SkTime::GetNSecs()
>
>    - Move high-precision wall timers from tools/timer to SkTime.
>    - Implement SkTime::GetMSecs() in terms of SkTime::GetNSecs().
>    - Delete unused tools/timer code.
>
> I have no idea what's going on there in src/animator.
> I don't intend to investigate.
>
> BUG=skia:
>
> Committed: https://skia.googlesource.com/skia/+/70084cbc16ee8162649f2601377feb6e49de0217
>
> CQ_EXTRA_TRYBOTS=client.skia.compile:Build-Ubuntu-GCC-x86_64-Debug-CrOS_Link-Trybot
>
> Committed: https://skia.googlesource.com/skia/+/a1840d50e29fd95e4df2d1168fe54c34c2a5c30c
>
> Committed: https://skia.googlesource.com/skia/+/38a88e4c0c28a7be981aac7bb4a198ad95a62a63

TBR=caryclark@google.com,reed@google.com,mtklein@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review URL: https://codereview.chromium.org/1422623003

1 files changed, 53 insertions, 0 deletions

diff --git a/tools/timer/SysTimer_windows.cpp b/tools/timer/SysTimer_windows.cpp
new file mode 100644
index 0000000000..8e45b4a68e
--- /dev/null
+++ b/tools/timer/SysTimer_windows.cpp
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#include "SysTimer_windows.h"
+
+#include <intrin.h>
+
+static ULONGLONG win_cpu_time() {
+    FILETIME createTime;
+    FILETIME exitTime;
+    FILETIME usrTime;
+    FILETIME sysTime;
+    if (0 == GetProcessTimes(GetCurrentProcess(), &createTime, &exitTime, &sysTime, &usrTime)) {
+        return 0;
+    }
+    ULARGE_INTEGER start_cpu_sys;
+    ULARGE_INTEGER start_cpu_usr;
+    start_cpu_sys.LowPart  = sysTime.dwLowDateTime;
+    start_cpu_sys.HighPart = sysTime.dwHighDateTime;
+    start_cpu_usr.LowPart  = usrTime.dwLowDateTime;
+    start_cpu_usr.HighPart = usrTime.dwHighDateTime;
+    return start_cpu_sys.QuadPart + start_cpu_usr.QuadPart;
+}
+
+void SysTimer::startCpu() {
+    fStartCpu = win_cpu_time();
+}
+
+double SysTimer::endCpu() {
+    ULONGLONG end_cpu = win_cpu_time();
+    return static_cast<double>(end_cpu - fStartCpu) / 10000.0L;
+}
+
+// On recent Intel chips (roughly, "has Core or Atom in its name") __rdtsc will always tick
+// at the CPU's maximum rate, even while power management clocks the CPU up and down.
+// That's great, because it makes measuring wall time super simple.
+
+void SysTimer::startWall() {
+    fStartWall = __rdtsc();
+}
+
+double SysTimer::endWall() {
+    unsigned __int64 end = __rdtsc();
+
+    // This seems to, weirdly, give the CPU frequency in kHz.  That's exactly what we want!
+    LARGE_INTEGER freq_khz;
+    QueryPerformanceFrequency(&freq_khz);
+
+    return static_cast<double>(end - fStartWall) / static_cast<double>(freq_khz.QuadPart);
+}