Make it possible to run a test in sky_shell

sky/shell/testing/test_runner.cc

+// Copyright 2014 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 "sky/shell/testing/test_runner.h"
+
+#include <iostream>
+
+#include "base/bind.h"
+#include "base/message_loop/message_loop.h"
+#include "base/strings/string_util.h"
+#include "sky/shell/platform_view.h"
+#include "sky/shell/shell.h"
+#include "sky/shell/shell_view.h"
+
+namespace sky {
+namespace shell {
+namespace {
+
+struct UrlData {
+  std::string url;
+  std::string expected_pixel_hash;
+  bool enable_pixel_dumping = false;
+};
+
+void WaitForURL(UrlData& data) {

[eseidel, 2015/06/29 16:53:59]

This code is banana pants.  file://path/to/test?hash=HASH would made slightly
more sense (although admittedly not a huge amount).

+  // A test name is formated like file:///path/to/test'--pixel-test'pixelhash
+  std::cin >> data.url;
+
+  std::string pixel_switch;
+  std::string::size_type separator_position = data.url.find('\'');
+  if (separator_position != std::string::npos) {
+    pixel_switch = data.url.substr(separator_position + 1);
+    data.url.erase(separator_position);
+  }
+
+  std::string pixel_hash;
+  separator_position = pixel_switch.find('\'');
+  if (separator_position != std::string::npos) {
+    pixel_hash = pixel_switch.substr(separator_position + 1);
+    pixel_switch.erase(separator_position);
+  }
+
+  data.enable_pixel_dumping = pixel_switch == "--pixel-test";
+  data.expected_pixel_hash = pixel_hash;
+}
+
+const char kFileUrlPrefix[] = "file://";
+static TestRunner* g_test_runner = nullptr;
+
+}  // namespace
+
+TestRunner::TestRunner()
+  : shell_view_(new ShellView(Shell::Shared())),
+    weak_ptr_factory_(this) {
+  CHECK(!g_test_runner) << "Only create one TestRunner.";
+
+  shell_view_->view()->ConnectToViewportObserver(GetProxy(&viewport_observer_));
+  viewport_observer_->OnViewportMetricsChanged(320, 640, 1.0);

[eseidel, 2015/06/29 16:53:59]

How did we standardize on sub-VGA?

[abarth-chromium, 2015/06/30 21:38:31]

We can change this to be whatever you like.  This value matches the value in the
existing test runner.

+}
+
+TestRunner::~TestRunner() {
+}
+
+TestRunner& TestRunner::Shared() {
+  if (!g_test_runner)
+    g_test_runner = new TestRunner();
+  return *g_test_runner;
+}
+
+void TestRunner::Start(const std::string& single_test_url) {
+  single_test_url_ = single_test_url;
+  std::cout << "#READY\n";

[eseidel, 2015/06/29 16:53:59]

You're gonna want a helper for all these flush-every-line commands.  Or maybe
you can set cout into a flush-on-newline mode?

+  std::cout.flush();
+  ScheduleRun();
+}
+
+void TestRunner::OnTestComplete(const mojo::String& test_result,
+                                const mojo::Array<uint8_t> pixels) {
+  std::cout << "Content-Type: text/plain\n";
+  std::cout << test_result << "\n";
+  std::cout << "#EOF\n";

[eseidel, 2015/06/29 16:53:58]

Comments here as to what goes between the various #EOFs would be nice.

+  std::cout << "#EOF\n";
+  std::cout.flush();
+  std::cerr << "#EOF\n";
+  std::cerr.flush();
+  bindings_.CloseAllBindings();
+
+  if (single_test_url_.length())
+    exit(0);
+  ScheduleRun();
+}
+
+void TestRunner::DispatchInputEvent(mojo::EventPtr event) {
+  // TODO(abarth): Not implemented.
+}
+
+void TestRunner::Create(mojo::ApplicationConnection* app,
+                        mojo::InterfaceRequest<TestHarness> request) {
+  bindings_.AddBinding(this, request.Pass());
+}
+
+void TestRunner::ScheduleRun() {
+  base::MessageLoop::current()->PostTask(FROM_HERE,
+      base::Bind(&TestRunner::Run, weak_ptr_factory_.GetWeakPtr()));
+}
+
+void TestRunner::Run() {
+  UrlData data;
+  if (single_test_url_.length()) {
+    data.url = single_test_url_;
+  } else {
+    WaitForURL(data);
+  }
+
+  std::cout << "#BEGIN\n";
+  std::cout.flush();
+
+  if (StartsWithASCII(data.url, kFileUrlPrefix, true))
+    ReplaceFirstSubstringAfterOffset(&data.url, 0, kFileUrlPrefix, "");
+  viewport_observer_->RunFromFile(data.url, package_root_);
+}
+
+}  // namespace shell
+}  // namespace sky