Add a chrome://webapks page.

chrome/browser/android/webapk/webapk_info.h

+// Copyright (c) 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_ANDROID_WEBAPK_WEBAPK_INFO_H_
+#define CHROME_BROWSER_ANDROID_WEBAPK_WEBAPK_INFO_H_
+
+#include <string>
+
+// Structure with information about a WebAPK.
+struct WebApkInfo {
+  WebApkInfo(const std::string& short_name,
+             const std::string& package_name,
+             int shell_apk_version,
+             int version_code);
+  ~WebApkInfo();
+
+  // Short name of the WebAPK.
+  const std::string short_name;
+
+  // Package name of the WebAPK.
+  const std::string package_name;
+
+  // Shell APK version of the WebAPK.
+  const int shell_apk_version;
+
+  // Version code of the WebAPK.
+  const int version_code;

[dominickn, 2017/01/23 00:48:07]

#include "base/macros.h"

 private:
  DISALLOW_COPY_AND_ASSIGN(WebApkInfo);

[pkotwicz, 2017/01/23 15:44:51]

I know that it is normal to DISALLOW_COPY_AND_ASSIGN classes but I didn't know
this was also the case with structs. e.g. shortcut_info.h

[gonzalon, 2017/01/23 16:58:51]

I'm having some trouble with this. I updated the rest of the comments, but when
adding this line I get some strange errors. When looking for a solution I found
that using DISALLOW_COPY_AND_ASSIGN is apparently discouraged? Maybe it doesn't
apply for Chromium.
https://engdoc.corp.google.com/eng/doc/devguide/cpp/styleguide.shtml?cl=head#...

I got some errors that were not very descriptive when using this struct if I add
this line, I was wondering if there's anything in particular I need to keep in
mind when adding it? 

[dominickn, 2017/01/24 02:55:22]

For now, Chromium's style guide is to use DISALLOW_COPY_AND_ASSIGN (we differ
from the google style guide in some places). There are definitely structs which
use this (e.g. ContextualSearchContext).

The errors are exposing the fact that you're copying this struct in multiple
places. There's three copies in ShortcutHelper::OnWebApksRetrieved when filling
a std::vector - converting the string from Java to C++ (1x copy), then each
WebApkInfo is constructed (2x copy), then copied into the vector (3x copy).
There's also another copy in WebApksHandler (4x copy). That's a lot of calls to
malloc.

IMO, reducing the number of copies is highly desirable. To do so, you should
make this class movable. Then you can construct it by std::move'ing the strings
from the std::vector<std::string> in OnWebApksRetrieved, and then move it into
the std::vector<WebApkInfo>. That way, we have 1x copy per string (the
conversion from Java string to C++ string), and no more.

1. defining the move constructor/operator as default

WebApkInfo(WebApkInfo&& other) = default;
WebApkInfo& operator=(WebApkInfo&& other) = default;

2. removing const from the WebApkInfo members (can't move when members are
const; the whole thing is passed in a const vector so that stops modification)

3. in-place constructing the WebApkInfo in the push_back call, with a slightly
modification to the constructor:

WebApkInfo(std::string&& short_name, std::string&& package_name, int
shell_apk_version, int version_code);

std::vector<WebApkInfo> webapk_list;
webapk_list.reserve(short_names.size());
for (...) {
  webapk_list.push_back(WebApkInfo(std::move(short_names[i], package_names[i],
shell_apk_versions[i], version_codes[i]);
}

4. Make WebApksHandler using a reference, not value.

5. using DISALLOW_COPY_AND_ASSIGN

What do you think?

+};
+
+#endif  // CHROME_BROWSER_ANDROID_WEBAPK_WEBAPK_INFO_H_