[ios] BubbleViewController and BubbleView stubs.

ios/chrome/browser/ui/bubble/bubble_view_controller_unittest.mm

+// 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.
+
+#import "ios/chrome/browser/ui/bubble/bubble_view_controller.h"
+
+#include "base/logging.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "testing/platform_test.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+// Fixture to test BubbleViewController.
+class BubbleViewControllerTest : public PlatformTest {};
+
+// Tests the bubble's intrinsic content size given short text.
+TEST_F(BubbleViewControllerTest, BubbleSizeShortText) {}
+
+// Tests that the bubble accommodates text that exceeds the maximum bubble width
+// by displaying the text on multiple lines.
+TEST_F(BubbleViewControllerTest, BubbleSizeMultipleLineText) {}
+
+// Tests that the bubble attaches to the UI element when the layout is flipped
+// for RTL languages.
+TEST_F(BubbleViewControllerTest, RTL) {}
+
+// Tests that the accessibility label matches the display text.
+TEST_F(BubbleViewControllerTest, Accessibility) {}