Add a row in the network tray to inform users to turn Bluetooth on to enable Tether.

ash/system/tray/tray_info_label_unittest.cc

+// Copyright 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.
+
+#include "ash/system/tray/tray_info_label.h"
+
+#include "ash/test/ash_test_base.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "ui/accessibility/ax_node_data.h"
+
+namespace ash {
+
+namespace {
+
+class TestClickEvent : public ui::Event {
+ public:
+  TestClickEvent() : ui::Event(ui::ET_MOUSE_PRESSED, base::TimeTicks(), 0) {}
+};
+
+class TestDelegate : public TrayInfoLabel::Delegate {
+ public:
+  TestDelegate() {}
+
+  const std::vector<int>& clicked_message_ids() { return clicked_message_ids_; }
+
+  void AddClickableMessageId(int message_id) {
+    clickable_message_ids_.insert(message_id);
+  }
+
+  // TrayInfoLabel::Delegate:
+  void OnLabelClicked(int message_id) override {
+    clicked_message_ids_.push_back(message_id);
+  }
+
+  bool IsLabelClickable(int message_id) override {
+    return clickable_message_ids_.find(message_id) !=
+           clickable_message_ids_.end();
+  }
+
+ private:
+  std::set<int> clickable_message_ids_;

[Kyle Horimoto, 2017/07/14 20:58:50]

unordered_set

[lesliewatkins, 2017/07/18 17:00:06]

Done.

+  std::vector<int> clicked_message_ids_;
+};
+
+}  // namespace
+
+class TrayInfoLabelTest : public test::AshTestBase {
+ public:
+  void TearDown() override {
+    AshTestBase::TearDown();
+    label_.reset();
+    delegate_.reset();
+  }
+
+  void CreateLabel(bool use_delegate, int message_id) {
+    if (use_delegate)
+      delegate_ = base::MakeUnique<TestDelegate>();
+
+    label_ = base::MakeUnique<TrayInfoLabel>(delegate_.get(), message_id);
+  }
+
+  void ClickOnLabel(bool expect_click_was_handled) {
+    bool click_was_handled = label_->PerformAction(TestClickEvent());
+    EXPECT_EQ(expect_click_was_handled, click_was_handled);
+  }
+
+  void VerifyClickability(bool expected_clickable) {
+    EXPECT_EQ(expected_clickable, label_->IsClickable());
+
+    ui::AXNodeData node_data;
+    label_->GetAccessibleNodeData(&node_data);
+
+    if (expected_clickable)
+      EXPECT_EQ(ui::AX_ROLE_BUTTON, node_data.role);
+    else
+      EXPECT_EQ(ui::AX_ROLE_LABEL_TEXT, node_data.role);
+  }
+
+  void VerifyClicks(const std::vector<int>& expected_clicked_message_ids) {
+    if (!delegate_) {
+      EXPECT_TRUE(expected_clicked_message_ids.empty());
+      return;
+    }
+
+    EXPECT_EQ(expected_clicked_message_ids, delegate_->clicked_message_ids());
+  }
+
+  void VerifyNoClicks() { VerifyClicks(std::vector<int>()); }
+
+ protected:
+  std::unique_ptr<TrayInfoLabel> label_;
+  std::unique_ptr<TestDelegate> delegate_;
+};
+
+TEST_F(TrayInfoLabelTest, NoDelegate) {
+  CreateLabel(false /* use_delegate */, 0 /* message_id */);
+  VerifyClickability(false);
+
+  label_->Update(1 /* message_id */);
+  VerifyClickability(false);
+
+  label_->Update(2 /* message_id */);
+  VerifyClickability(false);
+}
+
+TEST_F(TrayInfoLabelTest, PerformAction) {
+  int clickable_message_id_1 = 1;

[Kyle Horimoto, 2017/07/14 20:58:49]

const int kClickableMessageId1 = 1;
const int kClickableMessageId2 = 2;
const int kNonClickableMessageId = 3;

[lesliewatkins, 2017/07/18 17:00:06]

Done.

+  int clickable_message_id_2 = 2;
+
+  int non_clickable_message_id = 0;

[Kyle Horimoto, 2017/07/14 20:58:49]

nit: Remove newline before this, add newline after this.

[lesliewatkins, 2017/07/18 17:00:06]

Done.

+  CreateLabel(true /* use_delegate */, clickable_message_id_1);
+  delegate_->AddClickableMessageId(clickable_message_id_1);
+  delegate_->AddClickableMessageId(clickable_message_id_2);
+  VerifyNoClicks();
+
+  ClickOnLabel(true /* expect_click_was_handled */);
+  VerifyClicks(std::vector<int>({clickable_message_id_1}));

[Kyle Horimoto, 2017/07/14 20:58:50]

nit: No parentheses around the vector literal:

std::vector<int>{kClickableMessageId1}

I believe the extra set of parentheses causes an extra unnecessary copy to be
performed.

[lesliewatkins, 2017/07/18 17:00:06]

Good to know!

+
+  ClickOnLabel(true /* expect_click_was_handled */);
+  VerifyClicks(
+      std::vector<int>({clickable_message_id_1, clickable_message_id_1}));
+
+  label_->Update(non_clickable_message_id);
+  ClickOnLabel(false /* expect_click_was_handled */);
+  VerifyClicks(
+      std::vector<int>({clickable_message_id_1, clickable_message_id_1}));
+
+  label_->Update(clickable_message_id_2);
+  ClickOnLabel(true /* expect_click_was_handled */);
+  VerifyClicks(std::vector<int>({clickable_message_id_1, clickable_message_id_1,
+                                 clickable_message_id_2}));
+}
+
+TEST_F(TrayInfoLabelTest, UpdateWithDelegate) {

[Kyle Horimoto, 2017/07/14 20:58:49]

Instead of having a separate test, let's just fold this into the test above and
remove this test entirely.

To do so, just add VerifyClickability() after each call to Update() before the
subsequent call to ClickOnLabel().

+  int clickable_message_id = 1;
+  int non_clickable_message_id = 0;
+  CreateLabel(true /* use_delegate */, non_clickable_message_id);
+  delegate_->AddClickableMessageId(clickable_message_id);
+  VerifyClickability(false);
+
+  label_->Update(clickable_message_id);
+  VerifyClickability(true);
+
+  label_->Update(non_clickable_message_id);
+  VerifyClickability(false);
+}
+
+}  // namespace ash