[release-branch.go1.13] cmd/trace: update to use WebComponents V0 pol…

…yfill

Old trace viewer stopped working with Chrome M80+ because the
old trace viewer heavily depended on WebComponents V0 which are deprecated.
Trace viewer recently migrated to use WebComponents V0 polyfill
(crbug.com/1036492). This CL brings in the newly updated trace_viewer_full.html
(sync'd @ 9508452e)
and updates the javascript snippet included in the /trace endpoint
to use the polyfill.

This brings in webcomponents.min.js copied from
https://chromium.googlesource.com/catapult/+/9508452e18f130c98499cb4c4f1e1efaedee8962/third_party/polymer/components/webcomponentsjs/webcomponents.min.js

That is necessary because the /trace endpoint needs to import
the vulcanized trace_viewer_full.html.

It's possible that some features are not working correctly with
this polyfill. In that case, report the issue to crbug.com/1036492.
There will be a warning message in the UI (yellow banner above the timeline)
which can be hidden by clicking the 'hide' button.

This allows to render the trace in browsers other than chrome in theory,
but I observed some buttons and functions still don't work outside
chrome.

Updates #34374.
Fixes #37342.

Change-Id: Ib575f756f5e6b22ad904ede6e4d224a995ebe259
Reviewed-on: https://go-review.googlesource.com/c/go/+/219997
Run-TryBot: Hyang-Ah Hana Kim <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Austin Clements <[email protected]>
(cherry picked from commit 75ea964)
Reviewed-on: https://go-review.googlesource.com/c/go/+/220321
Run-TryBot: Dmitri Shuralyov <[email protected]>

misc/trace/README.md

@@ -1,17 +1,41 @@
-This directory contains helper file for trace viewer (`go tool trace`).
+## Resources for Go's trace viewer
 
-`trace_viewer_full.html` was generated by following
-[instructions](https://github.com/catapult-project/catapult/blob/master/tracing/docs/embedding-trace-viewer.md)
-on revision `dc970d3e1f7b3da5a2849de70ff253acdb70148f`
-of [catapult](https://github.com/catapult-project/catapult) using:
+Go execution trace UI (`go tool trace`) embeds
+Chrome's trace viewer (Catapult) following the 
+[instructions](
+https://chromium.googlesource.com/catapult/+/refs/heads/master/tracing/docs/embedding-trace-viewer.md). This directory contains
+the helper files to embed Chrome's trace viewer.
+
+The current resources were generated/copied from
+[`Catapult@9508452e18f130c98499cb4c4f1e1efaedee8962`](
+https://chromium.googlesource.com/catapult/+/9508452e18f130c98499cb4c4f1e1efaedee8962).
+
+### Updating `trace_viewer_full.html`
+
+The file was generated by catapult's `vulcanize_trace_viewer` command.
 ```
-catapult$ ./tracing/bin/vulcanize_trace_viewer --config=full
-catapult$ cp tracing/bin/trace_viewer_full.html $GOROOT/misc/trace/trace_viewer_lean.html
+$ git clone https://chromium.googlesource.com/catapult
+$ cd catapult
+$ ./tracing/bin/vulcanize_trace_viewer --config=full
+$ cp tracing/bin/trace_viewer_full.html $GOROOT/misc/trace/trace_viewer_full.html
 ```
+
 We are supposed to use --config=lean (produces smaller html),
 but it is broken at the moment:
 https://github.com/catapult-project/catapult/issues/2247
 
+### Updating `webcomponents.min.js`
+
+`webcomponents.min.js` is necessary to let the trace viewer page
+to import the `trace_viewer_full.html`.
+This is copied from the catapult repo.
+
+```
+$ cp third_party/polymer/components/webcomponentsjs/webcomponents.min.js $GOROOT/misc/trace/webcomponents.min.js
+```
+
+## Licenses
+
 The license for trace-viewer is as follows:
 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 //
@@ -40,3 +64,42 @@ The license for trace-viewer is as follows:
 // 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.
+
+The license for webcomponents.min.js is as follows:
+
+/**
+ * @license
+ * Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
+ * This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+ * The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+ * The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+ * Code distributed by Google as part of the polymer project is also
+ * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+ */
+// Copyright (c) 2014 The Polymer Authors. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * 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.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// 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
+// OWNER 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.