Fix events_test_support layering violation, missing dependencies

EventGenerator currently depends on a backreference for the
EventGeneratorDelegate factory function, which it can get away with in
gyp because events_test_support is statically linked.

This CL solves the layering violation by requiring TestHelper and
TestBase classes that require the event generator to initialize a
default delegate, similar to how ViewsDelegate solves a similar layering
problem. It was tested by temporarily making events_test_support a
component library, which exposed some missing dependencies.

With this, events_unittests links properly with GN, with sources
matching gyp.

BUG=399106
R=brettw@chromium.org,sadrul@chromium.org,oshima@chromium.org
TBR=sky@chromium.org

Review URL: https://codereview.chromium.org/429803005

Cr-Commit-Position: refs/heads/master@{#288663}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288663 0039d316-1c4b-4281-b951-d872f2087c98

17 files changed, 187 insertions, 76 deletions

diff --git a/ash/test/ash_test_helper.cc b/ash/test/ash_test_helper.cc
index ceb2910..b9f8ece 100644
--- a/ash/test/ash_test_helper.cc
+++ b/ash/test/ash_test_helper.cc
@@ -19,6 +19,7 @@
 #include "ui/aura/env.h"
 #include "ui/aura/input_state_lookup.h"
 #include "ui/aura/test/env_test_helper.h"
+#include "ui/aura/test/event_generator_delegate_aura.h"
 #include "ui/base/ime/input_method_initializer.h"
 #include "ui/compositor/scoped_animation_duration_scale_mode.h"
 #include "ui/compositor/test/context_factories_for_test.h"
@@ -51,6 +52,7 @@ AshTestHelper::AshTestHelper(base::MessageLoopForUI* message_loop)
 #if defined(USE_X11)
   aura::test::SetUseOverrideRedirectWindowByDefault(true);
 #endif
+  aura::test::InitializeAuraEventGeneratorDelegate();
 }
 
 AshTestHelper::~AshTestHelper() {
diff --git a/athena/test/athena_test_base.cc b/athena/test/athena_test_base.cc
index a8ee6d3..8ddc437 100644
--- a/athena/test/athena_test_base.cc
+++ b/athena/test/athena_test_base.cc
@@ -5,6 +5,7 @@
 #include "athena/test/athena_test_base.h"
 
 #include "athena/test/athena_test_helper.h"
+#include "ui/aura/test/event_generator_delegate_aura.h"
 #include "ui/compositor/test/context_factories_for_test.h"
 
 #if defined(USE_X11)
@@ -38,6 +39,7 @@ void AthenaTestBase::SetUp() {
 #if defined(USE_X11)
   aura::test::SetUseOverrideRedirectWindowByDefault(true);
 #endif
+  aura::test::InitializeAuraEventGeneratorDelegate();
   helper_->SetUp(context_factory);
 }
 
diff --git a/content/public/test/browser_test_base.cc b/content/public/test/browser_test_base.cc
index 3493242..e31d937 100644
--- a/content/public/test/browser_test_base.cc
+++ b/content/public/test/browser_test_base.cc
@@ -42,6 +42,7 @@
 
 #if defined(USE_AURA)
 #include "content/browser/compositor/image_transport_factory.h"
+#include "ui/aura/test/event_generator_delegate_aura.h"
 #if defined(USE_X11)
 #include "ui/aura/window_tree_host_x11.h"
 #endif
@@ -132,9 +133,12 @@ BrowserTestBase::BrowserTestBase()
   base::mac::SetOverrideAmIBundled(true);
 #endif
 
-#if defined(USE_AURA) && defined(USE_X11)
+#if defined(USE_AURA)
+#if defined(USE_X11)
   aura::test::SetUseOverrideRedirectWindowByDefault(true);
 #endif
+  aura::test::InitializeAuraEventGeneratorDelegate();
+#endif
 
 #if defined(OS_POSIX)
   handle_sigterm_ = true;
diff --git a/ui/aura/test/aura_test_helper.cc b/ui/aura/test/aura_test_helper.cc
index 7beca60..836cf03 100644
--- a/ui/aura/test/aura_test_helper.cc
+++ b/ui/aura/test/aura_test_helper.cc
@@ -12,6 +12,7 @@
 #include "ui/aura/env.h"
 #include "ui/aura/input_state_lookup.h"
 #include "ui/aura/test/env_test_helper.h"
+#include "ui/aura/test/event_generator_delegate_aura.h"
 #include "ui/aura/test/test_focus_client.h"
 #include "ui/aura/test/test_screen.h"
 #include "ui/aura/test/test_window_tree_client.h"
@@ -43,6 +44,7 @@ AuraTestHelper::AuraTestHelper(base::MessageLoopForUI* message_loop)
 #if defined(USE_X11)
   test::SetUseOverrideRedirectWindowByDefault(true);
 #endif
+  InitializeAuraEventGeneratorDelegate();
 }
 
 AuraTestHelper::~AuraTestHelper() {
diff --git a/ui/aura/test/event_generator_delegate_aura.cc b/ui/aura/test/event_generator_delegate_aura.cc
index a32ab5b..a4041a3 100644
--- a/ui/aura/test/event_generator_delegate_aura.cc
+++ b/ui/aura/test/event_generator_delegate_aura.cc
@@ -4,6 +4,7 @@
 
 #include "ui/aura/test/event_generator_delegate_aura.h"
 
+#include "base/memory/singleton.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/aura/window_tree_host.h"
@@ -14,11 +15,18 @@ namespace {
 
 class DefaultEventGeneratorDelegate : public EventGeneratorDelegateAura {
  public:
-  explicit DefaultEventGeneratorDelegate(Window* root_window)
-      : root_window_(root_window) {}
-  virtual ~DefaultEventGeneratorDelegate() {}
+  static DefaultEventGeneratorDelegate* GetInstance() {
+    return Singleton<DefaultEventGeneratorDelegate>::get();
+  }
+
+  // EventGeneratorDelegate:
+  virtual void SetContext(ui::test::EventGenerator* owner,
+                          gfx::NativeWindow root_window,
+                          gfx::NativeWindow window) OVERRIDE {
+    root_window_ = root_window;
+  }
 
-  // EventGeneratorDelegateAura overrides:
+  // EventGeneratorDelegateAura:
   virtual WindowTreeHost* GetHostAt(const gfx::Point& point) const OVERRIDE {
     return root_window_->GetHost();
   }
@@ -29,6 +37,18 @@ class DefaultEventGeneratorDelegate : public EventGeneratorDelegateAura {
   }
 
  private:
+  friend struct DefaultSingletonTraits<DefaultEventGeneratorDelegate>;
+
+  DefaultEventGeneratorDelegate() : root_window_(NULL) {
+    DCHECK(!ui::test::EventGenerator::default_delegate);
+    ui::test::EventGenerator::default_delegate = this;
+  }
+
+  virtual ~DefaultEventGeneratorDelegate() {
+    DCHECK_EQ(this, ui::test::EventGenerator::default_delegate);
+    ui::test::EventGenerator::default_delegate = NULL;
+  }
+
   Window* root_window_;
 
   DISALLOW_COPY_AND_ASSIGN(DefaultEventGeneratorDelegate);
@@ -40,6 +60,10 @@ const Window* WindowFromTarget(const ui::EventTarget* event_target) {
 
 }  // namespace
 
+void InitializeAuraEventGeneratorDelegate() {
+  DefaultEventGeneratorDelegate::GetInstance();
+}
+
 EventGeneratorDelegateAura::EventGeneratorDelegateAura() {
 }
 
@@ -102,17 +126,3 @@ void EventGeneratorDelegateAura::ConvertPointFromHost(
 
 }  // namespace test
 }  // namespace aura
-
-namespace ui {
-namespace test {
-
-// static
-EventGeneratorDelegate* EventGenerator::CreateDefaultPlatformDelegate(
-    EventGenerator* owner,
-    gfx::NativeWindow root_window,
-    gfx::NativeWindow window) {
-  return new aura::test::DefaultEventGeneratorDelegate(root_window);
-}
-
-}  // namespace test
-}  // namespace ui
diff --git a/ui/aura/test/event_generator_delegate_aura.h b/ui/aura/test/event_generator_delegate_aura.h
index 5850789..5d37538 100644
--- a/ui/aura/test/event_generator_delegate_aura.h
+++ b/ui/aura/test/event_generator_delegate_aura.h
@@ -17,6 +17,8 @@ class ScreenPositionClient;
 
 namespace test {
 
+void InitializeAuraEventGeneratorDelegate();
+
 // Implementation of ui::test::EventGeneratorDelegate for Aura.
 class EventGeneratorDelegateAura : public ui::test::EventGeneratorDelegate {
  public:
diff --git a/ui/events/BUILD.gn b/ui/events/BUILD.gn
index 4de4301..7a868b1 100644
--- a/ui/events/BUILD.gn
+++ b/ui/events/BUILD.gn
@@ -218,6 +218,8 @@ source_set("test_support") {
   sources = [
     "test/cocoa_test_event_utils.h",
     "test/cocoa_test_event_utils.mm",
+    "test/event_generator.cc",
+    "test/event_generator.h",
     "test/events_test_utils.cc",
     "test/events_test_utils.h",
     "test/events_test_utils_x11.cc",
@@ -235,9 +237,12 @@ source_set("test_support") {
   ]
 
   deps = [
+    "//base",
     "//skia",
+    "//ui/gfx/geometry",
     ":events_base",
     ":events",
+    ":gesture_detection",
   ]
 
   if (is_ios) {
@@ -247,9 +252,7 @@ source_set("test_support") {
     ]
   }
 
-  if (use_x11) {
-    configs += [ "//build/config/linux:x11" ]
-  } else {
+  if (!use_x11) {
     sources -= [
       "test/events_test_utils_x11.cc",
       "test/events_test_utils_x11.h",
@@ -278,7 +281,9 @@ test("events_unittests") {
     "x/events_x_unittest.cc",
   ]
 
-  if (!use_x11) {
+  if (use_x11) {
+    configs += [ "//build/config/linux:x11" ]
+  } else {
     sources -= [
       "x/events_x_unittest.cc",
     ]
diff --git a/ui/events/events.gyp b/ui/events/events.gyp
index ceeddfb..cb4c0ca 100644
--- a/ui/events/events.gyp
+++ b/ui/events/events.gyp
@@ -149,6 +149,11 @@
         'linux/text_edit_key_bindings_delegate_auralinux.h',
       ],
       'conditions': [
+        ['use_x11==1', {
+          'dependencies': [
+            '../../build/linux/system.gyp:x11',
+          ],
+        }],
         ['use_aura==0', {
           'sources!': [
             'gestures/gesture_point.cc',
@@ -245,9 +250,12 @@
       'target_name': 'events_test_support',
       'type': 'static_library',
       'dependencies': [
+        '<(DEPTH)/base/base.gyp:base',
         '<(DEPTH)/skia/skia.gyp:skia',
+        '../gfx/gfx.gyp:gfx_geometry',
         'events',
         'events_base',
+        'gesture_detection',
         'platform/events_platform.gyp:events_platform',
       ],
       'sources': [
@@ -272,23 +280,10 @@
         'test/test_event_target.h',
       ],
       'conditions': [
-        ['use_x11==1', {
-          'dependencies': [
-            '../../build/linux/system.gyp:x11',
-            '../gfx/x/gfx_x11.gyp:gfx_x11',
-          ],
-        }],
         ['OS=="ios"', {
           # The cocoa files don't apply to iOS.
           'sources/': [['exclude', 'cocoa']],
         }],
-        ['OS == "android"', {
-          'sources!': [
-            # Event generator not yet ported to Android.
-            'test/event_generator.cc',
-            'test/event_generator.h',
-          ],
-        }],
       ],
     },
     {
@@ -335,6 +330,12 @@
         'x/events_x_unittest.cc',
       ],
       'conditions': [
+        ['use_x11==1', {
+          'dependencies': [
+            '../../build/linux/system.gyp:x11',
+            '../gfx/x/gfx_x11.gyp:gfx_x11',
+          ],
+        }],
         ['use_ozone==1', {
           'sources': [
             'ozone/evdev/key_event_converter_evdev_unittest.cc',
diff --git a/ui/events/test/event_generator.cc b/ui/events/test/event_generator.cc
index b4772e5..b17c801 100644
--- a/ui/events/test/event_generator.cc
+++ b/ui/events/test/event_generator.cc
@@ -58,44 +58,46 @@ const int kAllButtonMask = ui::EF_LEFT_MOUSE_BUTTON | ui::EF_RIGHT_MOUSE_BUTTON;
 
 }  // namespace
 
+EventGeneratorDelegate* EventGenerator::default_delegate = NULL;
+
 EventGenerator::EventGenerator(gfx::NativeWindow root_window)
-    : delegate_(CreateDefaultPlatformDelegate(this, root_window, NULL)),
-      current_target_(delegate_->GetTargetAt(current_location_)),
+    : current_target_(NULL),
       flags_(0),
       grab_(false),
       async_(false),
       tick_clock_(new base::DefaultTickClock()) {
+  Init(root_window, NULL);
 }
 
 EventGenerator::EventGenerator(gfx::NativeWindow root_window,
                                const gfx::Point& point)
-    : delegate_(CreateDefaultPlatformDelegate(this, root_window, NULL)),
-      current_location_(point),
-      current_target_(delegate_->GetTargetAt(current_location_)),
+    : current_location_(point),
+      current_target_(NULL),
       flags_(0),
       grab_(false),
       async_(false),
       tick_clock_(new base::DefaultTickClock()) {
+  Init(root_window, NULL);
 }
 
 EventGenerator::EventGenerator(gfx::NativeWindow root_window,
                                gfx::NativeWindow window)
-    : delegate_(CreateDefaultPlatformDelegate(this, root_window, window)),
-      current_location_(delegate_->CenterOfWindow(window)),
-      current_target_(delegate_->GetTargetAt(current_location_)),
+    : current_target_(NULL),
       flags_(0),
       grab_(false),
       async_(false),
       tick_clock_(new base::DefaultTickClock()) {
+  Init(root_window, window);
 }
 
 EventGenerator::EventGenerator(EventGeneratorDelegate* delegate)
     : delegate_(delegate),
-      current_target_(delegate_->GetTargetAt(current_location_)),
+      current_target_(NULL),
       flags_(0),
       grab_(false),
       async_(false),
       tick_clock_(new base::DefaultTickClock()) {
+  Init(NULL, NULL);
 }
 
 EventGenerator::~EventGenerator() {
@@ -103,6 +105,7 @@ EventGenerator::~EventGenerator() {
       i != pending_events_.end(); ++i)
     delete *i;
   pending_events_.clear();
+  delegate()->SetContext(NULL, NULL, NULL);
 }
 
 void EventGenerator::PressLeftButton() {
@@ -142,7 +145,7 @@ void EventGenerator::MoveMouseWheel(int delta_x, int delta_y) {
 
 void EventGenerator::SendMouseExit() {
   gfx::Point exit_location(current_location_);
-  delegate_->ConvertPointToTarget(current_target_, &exit_location);
+  delegate()->ConvertPointToTarget(current_target_, &exit_location);
   ui::MouseEvent mouseev(ui::ET_MOUSE_EXITED, exit_location, exit_location,
                          flags_, 0);
   Dispatch(&mouseev);
@@ -155,7 +158,7 @@ void EventGenerator::MoveMouseToInHost(const gfx::Point& point_in_host) {
   Dispatch(&mouseev);
 
   current_location_ = point_in_host;
-  delegate_->ConvertPointFromHost(current_target_, &current_location_);
+  delegate()->ConvertPointFromHost(current_target_, &current_location_);
 }
 
 void EventGenerator::MoveMouseTo(const gfx::Point& point_in_screen,
@@ -171,7 +174,7 @@ void EventGenerator::MoveMouseTo(const gfx::Point& point_in_screen,
     gfx::Point move_point = current_location_ + gfx::ToRoundedVector2d(step);
     if (!grab_)
       UpdateCurrentDispatcher(move_point);
-    delegate_->ConvertPointToTarget(current_target_, &move_point);
+    delegate()->ConvertPointToTarget(current_target_, &move_point);
     ui::MouseEvent mouseev(event_type, move_point, move_point, flags_, 0);
     Dispatch(&mouseev);
   }
@@ -181,7 +184,7 @@ void EventGenerator::MoveMouseTo(const gfx::Point& point_in_screen,
 void EventGenerator::MoveMouseRelativeTo(const EventTarget* window,
                                          const gfx::Point& point_in_parent) {
   gfx::Point point(point_in_parent);
-  delegate_->ConvertPointFromTarget(window, &point);
+  delegate()->ConvertPointFromTarget(window, &point);
   MoveMouseTo(point);
 }
 
@@ -494,6 +497,14 @@ base::TimeDelta EventGenerator::Now() {
       tick_clock_->NowTicks().ToInternalValue());
 }
 
+void EventGenerator::Init(gfx::NativeWindow root_window,
+                          gfx::NativeWindow window_context) {
+  delegate()->SetContext(this, root_window, window_context);
+  if (window_context)
+    current_location_ = delegate()->CenterOfWindow(window_context);
+  current_target_ = delegate()->GetTargetAt(current_location_);
+}
+
 void EventGenerator::DispatchKeyEvent(bool is_press,
                                       ui::KeyboardCode key_code,
                                       int flags) {
@@ -526,7 +537,7 @@ void EventGenerator::DispatchKeyEvent(bool is_press,
 }
 
 void EventGenerator::UpdateCurrentDispatcher(const gfx::Point& point) {
-  current_target_ = delegate_->GetTargetAt(point);
+  current_target_ = delegate()->GetTargetAt(point);
 }
 
 void EventGenerator::PressButton(int flag) {
@@ -553,12 +564,12 @@ void EventGenerator::ReleaseButton(int flag) {
 
 gfx::Point EventGenerator::GetLocationInCurrentRoot() const {
   gfx::Point p(current_location_);
-  delegate_->ConvertPointToTarget(current_target_, &p);
+  delegate()->ConvertPointToTarget(current_target_, &p);
   return p;
 }
 
 gfx::Point EventGenerator::CenterOfWindow(const EventTarget* window) const {
-  return delegate_->CenterOfTarget(window);
+  return delegate()->CenterOfTarget(window);
 }
 
 void EventGenerator::DoDispatchEvent(ui::Event* event, bool async) {
@@ -585,7 +596,7 @@ void EventGenerator::DoDispatchEvent(ui::Event* event, bool async) {
     }
     pending_events_.push_back(pending_event);
   } else {
-    ui::EventSource* event_source = delegate_->GetEventSource(current_target_);
+    ui::EventSource* event_source = delegate()->GetEventSource(current_target_);
     ui::EventSourceTestApi event_source_test(event_source);
     ui::EventDispatchDetails details =
         event_source_test.SendEventToProcessor(event);
@@ -607,5 +618,18 @@ void EventGenerator::DispatchNextPendingEvent() {
   }
 }
 
+const EventGeneratorDelegate* EventGenerator::delegate() const {
+  if (delegate_)
+    return delegate_.get();
+
+  DCHECK(default_delegate);
+  return default_delegate;
+}
+
+EventGeneratorDelegate* EventGenerator::delegate() {
+  return const_cast<EventGeneratorDelegate*>(
+      const_cast<const EventGenerator*>(this)->delegate());
+}
+
 }  // namespace test
 }  // namespace ui
diff --git a/ui/events/test/event_generator.h b/ui/events/test/event_generator.h
index 67360c4..bc243b9 100644
--- a/ui/events/test/event_generator.h
+++ b/ui/events/test/event_generator.h
@@ -36,12 +36,20 @@ namespace test {
 typedef base::Callback<void(EventType, const gfx::Vector2dF&)>
         ScrollStepCallback;
 
+class EventGenerator;
+
 // A delegate interface for EventGenerator to abstract platform-specific event
 // targeting and coordinate conversion.
 class EventGeneratorDelegate {
  public:
   virtual ~EventGeneratorDelegate() {}
 
+  // Set the context of the delegate, whilst it is being used by an active
+  // EventGenerator.
+  virtual void SetContext(EventGenerator* owner,
+                          gfx::NativeWindow root_window,
+                          gfx::NativeWindow window) {}
+
   // The ui::EventTarget at the given |location|.
   virtual EventTarget* GetTargetAt(const gfx::Point& location) = 0;
 
@@ -335,12 +343,12 @@ class EventGenerator {
   // Get the current time from the tick clock.
   base::TimeDelta Now();
 
+  // Default delegate set by a platform-specific GeneratorDelegate singleton.
+  static EventGeneratorDelegate* default_delegate;
+
  private:
-  // Implemented per-platform to create the default EventGeneratorDelegate.
-  static EventGeneratorDelegate* CreateDefaultPlatformDelegate(
-      EventGenerator* owner,
-      gfx::NativeWindow root_window,
-      gfx::NativeWindow window);
+  // Set up the test context using the delegate.
+  void Init(gfx::NativeWindow root_window, gfx::NativeWindow window_context);
 
   // Dispatch a key event to the WindowEventDispatcher.
   void DispatchKeyEvent(bool is_press, KeyboardCode key_code, int flags);
@@ -355,6 +363,9 @@ class EventGenerator {
   void DispatchNextPendingEvent();
   void DoDispatchEvent(Event* event, bool async);
 
+  const EventGeneratorDelegate* delegate() const;
+  EventGeneratorDelegate* delegate();
+
   scoped_ptr<EventGeneratorDelegate> delegate_;
   gfx::Point current_location_;
   EventTarget* current_target_;
diff --git a/ui/ui_unittests.gyp b/ui/ui_unittests.gyp
index ff09911..938b4d6 100644
--- a/ui/ui_unittests.gyp
+++ b/ui/ui_unittests.gyp
@@ -160,8 +160,10 @@
         }],
         ['use_x11==1', {
           'dependencies': [
+            '../build/linux/system.gyp:x11',
             '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
             'events/platform/x11/x11_events_platform.gyp:x11_events_platform',
+            'gfx/x/gfx_x11.gyp:gfx_x11',
           ],
         }],
         ['OS!="win" or use_aura==0', {
diff --git a/ui/views/test/event_generator_delegate_mac.h b/ui/views/test/event_generator_delegate_mac.h
new file mode 100644
index 0000000..86239ba
--- /dev/null
+++ b/ui/views/test/event_generator_delegate_mac.h
@@ -0,0 +1,16 @@
+// 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.
+
+#ifndef UI_VIEWS_TEST_EVENT_GENERATOR_DELEGATE_MAC_H_
+#define UI_VIEWS_TEST_EVENT_GENERATOR_DELEGATE_MAC_H_
+
+namespace views {
+namespace test {
+
+void InitializeMacEventGeneratorDelegate();
+
+}  // namespace test
+}  // namespace views
+
+#endif  // UI_VIEWS_TEST_EVENT_GENERATOR_DELEGATE_MAC_H_
diff --git a/ui/views/test/event_generator_delegate_mac.mm b/ui/views/test/event_generator_delegate_mac.mm
index 69fd88f..d0e351a 100644
--- a/ui/views/test/event_generator_delegate_mac.mm
+++ b/ui/views/test/event_generator_delegate_mac.mm
@@ -4,6 +4,7 @@
 
 #import <Cocoa/Cocoa.h>
 
+#include "base/memory/singleton.h"
 #include "ui/events/event_processor.h"
 #include "ui/events/event_target.h"
 #include "ui/events/event_target_iterator.h"
@@ -237,8 +238,9 @@ class EventGeneratorDelegateMac : public ui::EventTarget,
                                   public ui::EventTargeter,
                                   public ui::test::EventGeneratorDelegate {
  public:
-  EventGeneratorDelegateMac(ui::test::EventGenerator* owner, NSWindow* window);
-  virtual ~EventGeneratorDelegateMac() {}
+  static EventGeneratorDelegateMac* GetInstance() {
+    return Singleton<EventGeneratorDelegateMac>::get();
+  }
 
   // Overridden from ui::EventTarget:
   virtual bool CanAcceptEvent(const ui::Event& event) OVERRIDE { return true; }
@@ -263,6 +265,9 @@ class EventGeneratorDelegateMac : public ui::EventTarget,
   }
 
   // Overridden from ui::test::EventGeneratorDelegate:
+  virtual void SetContext(ui::test::EventGenerator* owner,
+                          gfx::NativeWindow root_window,
+                          gfx::NativeWindow window) OVERRIDE;
   virtual ui::EventTarget* GetTargetAt(const gfx::Point& location) OVERRIDE {
     return this;
   }
@@ -281,20 +286,28 @@ class EventGeneratorDelegateMac : public ui::EventTarget,
                                     gfx::Point* point) const OVERRIDE {}
 
  private:
+  friend struct DefaultSingletonTraits<EventGeneratorDelegateMac>;
+
+  EventGeneratorDelegateMac();
+  virtual ~EventGeneratorDelegateMac();
+
   ui::test::EventGenerator* owner_;
   NSWindow* window_;
-  ScopedClassSwizzler swizzle_pressed_;
+  scoped_ptr<ScopedClassSwizzler> swizzle_pressed_;
 
   DISALLOW_COPY_AND_ASSIGN(EventGeneratorDelegateMac);
 };
 
-EventGeneratorDelegateMac::EventGeneratorDelegateMac(
-    ui::test::EventGenerator* owner, NSWindow* window)
-    : owner_(owner),
-      window_(window),
-      swizzle_pressed_([NSEvent class],
-                       [NSEventDonor class],
-                       @selector(pressedMouseButtons)) {
+EventGeneratorDelegateMac::EventGeneratorDelegateMac()
+    : owner_(NULL),
+      window_(NULL) {
+  DCHECK(!ui::test::EventGenerator::default_delegate);
+  ui::test::EventGenerator::default_delegate = this;
+}
+
+EventGeneratorDelegateMac::~EventGeneratorDelegateMac() {
+  DCHECK_EQ(this, ui::test::EventGenerator::default_delegate);
+  ui::test::EventGenerator::default_delegate = NULL;
 }
 
 scoped_ptr<ui::EventTargetIterator>
@@ -312,6 +325,20 @@ void EventGeneratorDelegateMac::OnMouseEvent(ui::MouseEvent* event) {
                              event->changed_button_flags());
 }
 
+void EventGeneratorDelegateMac::SetContext(ui::test::EventGenerator* owner,
+                                           gfx::NativeWindow root_window,
+                                           gfx::NativeWindow window) {
+  swizzle_pressed_.reset();
+  owner_ = owner;
+  window_ = window;
+  if (owner_) {
+    swizzle_pressed_.reset(new ScopedClassSwizzler(
+        [NSEvent class],
+        [NSEventDonor class],
+        @selector(pressedMouseButtons)));
+  }
+}
+
 gfx::Point EventGeneratorDelegateMac::CenterOfTarget(
     const ui::EventTarget* target) const {
   DCHECK_EQ(target, this);
@@ -326,16 +353,12 @@ gfx::Point EventGeneratorDelegateMac::CenterOfWindow(
 
 }  // namespace
 
-namespace ui {
+namespace views {
 namespace test {
 
-// static
-EventGeneratorDelegate* EventGenerator::CreateDefaultPlatformDelegate(
-    EventGenerator* owner,
-    gfx::NativeWindow root_window,
-    gfx::NativeWindow window) {
-  return new EventGeneratorDelegateMac(owner, window);
+void InitializeMacEventGeneratorDelegate() {
+  EventGeneratorDelegateMac::GetInstance();
 }
 
 }  // namespace test
-}  // namespace ui
+}  // namespace views
diff --git a/ui/views/test/views_test_helper_mac.mm b/ui/views/test/views_test_helper_mac.mm
index b0eb85a..a50f4aa 100644
--- a/ui/views/test/views_test_helper_mac.mm
+++ b/ui/views/test/views_test_helper_mac.mm
@@ -5,6 +5,7 @@
 #include "ui/views/test/views_test_helper_mac.h"
 
 #include "ui/compositor/scoped_animation_duration_scale_mode.h"
+#include "ui/views/test/event_generator_delegate_mac.h"
 
 namespace views {
 
@@ -17,6 +18,7 @@ ViewsTestHelper* ViewsTestHelper::Create(base::MessageLoopForUI* message_loop,
 ViewsTestHelperMac::ViewsTestHelperMac()
     : zero_duration_mode_(new ui::ScopedAnimationDurationScaleMode(
           ui::ScopedAnimationDurationScaleMode::ZERO_DURATION)) {
+  test::InitializeMacEventGeneratorDelegate();
 }
 
 ViewsTestHelperMac::~ViewsTestHelperMac() {
diff --git a/ui/views/views.gyp b/ui/views/views.gyp
index 4376618..9d1bf02 100644
--- a/ui/views/views.gyp
+++ b/ui/views/views.gyp
@@ -448,6 +448,7 @@
       'test/desktop_test_views_delegate.h',
       'test/desktop_test_views_delegate_aura.cc',
       'test/desktop_test_views_delegate_mac.mm',
+      'test/event_generator_delegate_mac.h',
       'test/event_generator_delegate_mac.mm',
       'test/focus_manager_test.h',
       'test/focus_manager_test.cc',
diff --git a/ui/wm/BUILD.gn b/ui/wm/BUILD.gn
index 23b7792..def5803 100644
--- a/ui/wm/BUILD.gn
+++ b/ui/wm/BUILD.gn
@@ -80,6 +80,7 @@ component("wm") {
     "//ui/compositor",
     "//ui/events",
     "//ui/events:events_base",
+    "//ui/events/platform",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//ui/resources",
@@ -135,6 +136,7 @@ test("wm_unittests") {
     "//ui/compositor",
     "//ui/events",
     "//ui/events:events_base",
+    "//ui/events/platform",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
diff --git a/ui/wm/wm.gyp b/ui/wm/wm.gyp
index cfdc937..b743f76 100644
--- a/ui/wm/wm.gyp
+++ b/ui/wm/wm.gyp
@@ -18,6 +18,7 @@
         '../compositor/compositor.gyp:compositor',
         '../events/events.gyp:events',
         '../events/events.gyp:events_base',
+        '../events/platform/events_platform.gyp:events_platform',
         '../gfx/gfx.gyp:gfx_geometry',
         '../gfx/gfx.gyp:gfx',
         '../resources/ui_resources.gyp:ui_resources',
@@ -125,6 +126,7 @@
         '../compositor/compositor.gyp:compositor',
         '../events/events.gyp:events',
         '../events/events.gyp:events_base',
+        '../events/platform/events_platform.gyp:events_platform',
         '../gfx/gfx.gyp:gfx',
         '../gfx/gfx.gyp:gfx_geometry',
         'wm',