headless: Initial headless embedder API implementation

headless/app/headless_shell.cc

+// Copyright 2016 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.
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/command_line.h"
+#include "base/location.h"
+#include "base/memory/ref_counted.h"
+#include "base/strings/string_number_conversions.h"
+#include "content/public/common/content_switches.h"
+#include "headless/public/headless_browser.h"
+#include "headless/public/headless_web_contents.h"
+#include "ui/gfx/geometry/size.h"
+
+using headless::HeadlessBrowser;
+using headless::HeadlessWebContents;
+
+// A sample application which demonstrates the use of the headless API.
+class HeadlessShell : public HeadlessWebContents::Observer {
+ public:
+  HeadlessShell() : browser_(nullptr) {}
+  ~HeadlessShell() override {}
+
+  void OnStart(HeadlessBrowser* browser) {
+    browser_ = browser;
+    web_contents_ = browser->CreateWebContents({800, 600});

[Ryan Sleevi, 2016/02/22 22:01:21]

STYLE: This is still banned - https://chromium-cpp.appspot.com/#core-blacklist

(It's also entirely non-obvious that {800, 600} translates to a gfx::Size, fwiw)

[Sami, 2016/02/23 20:19:07]

Agreed & done.

+    Observe(web_contents_.get());
+
+    base::CommandLine::StringVector args =
+        base::CommandLine::ForCurrentProcess()->GetArgs();
+
+    const char kDefaultUrl[] = "https://google.com";
+    std::string url;
+    if (args.empty() || args[0].empty()) {
+      url = kDefaultUrl;
+    } else {
+      url = args[0];
+    }
+    web_contents_->OpenURL(GURL(url));

[Ryan Sleevi, 2016/02/22 22:01:21]

DESIGN: You do nothing to validate the well-formedness of this URL.

[Sami, 2016/02/23 20:19:07]

Added validation to OpenURL.

+  }
+
+  void StopIfNeeded() {
+    const base::CommandLine& command_line =
+        *base::CommandLine::ForCurrentProcess();
+    if (!command_line.HasSwitch(switches::kRemoteDebuggingPort))
+      browser_->Stop();
+  }
+
+  // HeadlessWebContents::Observer implementation:
+  void DocumentOnLoadCompletedInMainFrame() override {
+    LOG(INFO) << "Document load completed";
+    StopIfNeeded();
+  }
+
+ private:
+  HeadlessBrowser* browser_;  // Not owned.
+  scoped_ptr<HeadlessWebContents> web_contents_;
+
+  DISALLOW_COPY_AND_ASSIGN(HeadlessShell);
+};
+
+int main(int argc, const char** argv) {
+  HeadlessShell shell;
+  HeadlessBrowser::Options::Builder builder(argc, argv);
+
+  // Enable devtools if requested.
+  base::CommandLine command_line(argc, argv);
+  if (command_line.HasSwitch(switches::kRemoteDebuggingPort)) {
+    int temp_port;
+    std::string port_str =
+        command_line.GetSwitchValueASCII(switches::kRemoteDebuggingPort);
+    if (base::StringToInt(port_str, &temp_port) && temp_port >= 0 &&
+        temp_port < 65535) {

[Ryan Sleevi, 2016/02/22 21:11:13]

SECURITY/DESIGN: Please use base/numerics for conversions like this.

[Sami, 2016/02/23 20:19:07]

Thanks for the tip -- done.

+      builder.EnableDevToolsServer(static_cast<uint16_t>(temp_port));
+    }
+  }
+
+  return HeadlessBrowser::Run(
+      builder.Build(),
+      base::Bind(&HeadlessShell::OnStart, base::Unretained(&shell)));
+}