perf_hooks: implement histogram based api

Add a sampling-based event loop delay monitor.

```js
const { monitorEventLoopDelay } = require('perf_hooks');

const h = monitorEventLoopDelay();

h.enable();

h.disable();

console.log(h.percentiles);
console.log(h.min);
console.log(h.max);
console.log(h.mean);
console.log(h.stddev);
console.log(h.percentile(50));
```

PR-URL: nodejs#25378
Reviewed-By: Matteo Collina <[email protected]>
Reviewed-By: Gireesh Punathil <[email protected]>
Reviewed-By: Stephen Belanger <[email protected]>
Reviewed-By: Richard Lau <[email protected]>
Reviewed-By: Anna Henningsen <[email protected]>

LICENSE

@@ -1371,3 +1371,48 @@ The externally maintained libraries used by Node.js are:
     OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
     THE SOFTWARE.
   """
+
+- HdrHistogram, located at deps/histogram, is licensed as follows:
+  """
+    The code in this repository code was Written by Gil Tene, Michael Barker,
+    and Matt Warren, and released to the public domain, as explained at
+    http://creativecommons.org/publicdomain/zero/1.0/
+
+    For users of this code who wish to consume it under the "BSD" license
+    rather than under the public domain or CC0 contribution text mentioned
+    above, the code found under this directory is *also* provided under the
+    following license (commonly referred to as the BSD 2-Clause License). This
+    license does not detract from the above stated release of the code into
+    the public domain, and simply represents an additional license granted by
+    the Author.
+
+    -----------------------------------------------------------------------------
+    ** Beginning of "BSD 2-Clause License" text. **
+
+     Copyright (c) 2012, 2013, 2014 Gil Tene
+     Copyright (c) 2014 Michael Barker
+     Copyright (c) 2014 Matt Warren
+     All rights reserved.
+
+     Redistribution and use in source and binary forms, with or without
+     modification, are permitted provided that the following conditions are met:
+
+     1. Redistributions of source code must retain the above copyright notice,
+        this list of conditions and the following disclaimer.
+
+     2. Redistributions in binary form must reproduce the above copyright notice,
+        this list of conditions and the following disclaimer in the documentation
+        and/or other materials provided with the distribution.
+
+     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+     AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+     IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+     ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+     LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+     CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+     SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+     INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+     ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+     THE POSSIBILITY OF SUCH DAMAGE.
+  """

deps/histogram/LICENSE.txt

@@ -0,0 +1,41 @@
+The code in this repository code was Written by Gil Tene, Michael Barker,
+and Matt Warren, and released to the public domain, as explained at
+http://creativecommons.org/publicdomain/zero/1.0/
+
+For users of this code who wish to consume it under the "BSD" license
+rather than under the public domain or CC0 contribution text mentioned
+above, the code found under this directory is *also* provided under the
+following license (commonly referred to as the BSD 2-Clause License). This
+license does not detract from the above stated release of the code into
+the public domain, and simply represents an additional license granted by
+the Author.
+
+-----------------------------------------------------------------------------
+** Beginning of "BSD 2-Clause License" text. **
+
+ Copyright (c) 2012, 2013, 2014 Gil Tene
+ Copyright (c) 2014 Michael Barker
+ Copyright (c) 2014 Matt Warren
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ 1. Redistributions of source code must retain the above copyright notice,
+    this list of conditions and the following disclaimer.
+
+ 2. Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ THE POSSIBILITY OF SUCH DAMAGE.

deps/histogram/README.md

@@ -0,0 +1,3 @@
+# HdrHistogram_c
+
+From: https://github.com/HdrHistogram/HdrHistogram_c

deps/histogram/histogram.gyp

@@ -0,0 +1,15 @@
+{
+  'targets': [
+    {
+      'target_name': 'histogram',
+      'type': 'static_library',
+      'include_dirs': ['src'],
+      'direct_dependent_settings': {
+        'include_dirs': [ 'src' ]
+      },
+      'sources': [
+        'src/hdr_histogram.c',
+      ]
+    }
+  ]
+}