Revert TabletModeController refactoring cls.

The refacotring CLs exposed an underlying issue that caused b/117075672.
I need to revert all the refactoring for now, and fix the underlying issue
first and then reland these refactoring cls.

Basically the assumption of "--enable-touchview" USE flag is not longer true,
thus Chrome can't reply on this flag to decide whether a device is capable of
entering tablet mode. We need to find other ways to do so.

Since it's a pure revert, TBR xiyuan@.

Revert "TabletModeController refactoring II."

This reverts commit 43b3f48d.

Revert "TabletModeController refactoring III."

This reverts commit 95f93d44.

Revert "Fix the regression caused by the refactoring."

This reverts commit 5b0a138d.

Bug:887042, b/117075672
TBR=xiyuan@chromium.org

Change-Id: I494a8d05be1fb07bea404cd714b0b1d9689e46d4
Reviewed-on: https://chromium-review.googlesource.com/c/1265996Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597356}

ash/keyboard/virtual_keyboard_controller_unittest.cc

@@ -357,7 +357,7 @@ TEST_F(VirtualKeyboardControllerAutoTest, EnabledDuringTabletMode) {
   TabletModeControllerTestApi().EnterTabletMode();
   ASSERT_TRUE(keyboard::IsKeyboardEnabled());
   // Toggle tablet mode off.
-  TabletModeControllerTestApi().LeaveTabletMode();
+  TabletModeControllerTestApi().LeaveTabletMode(false);
   ASSERT_FALSE(keyboard::IsKeyboardEnabled());
 }
 
@@ -400,7 +400,7 @@ TEST_F(VirtualKeyboardControllerAutoTest, SuppressedInTabletMode) {
   ASSERT_TRUE(notified());
   ASSERT_FALSE(IsVirtualKeyboardSuppressed());
   // Toggle tablet mode oFF.
-  TabletModeControllerTestApi().LeaveTabletMode();
+  TabletModeControllerTestApi().LeaveTabletMode(false);
   ASSERT_FALSE(keyboard::IsKeyboardEnabled());
 }
 

ash/system/overview/overview_button_tray_unittest.cc

@@ -112,7 +112,7 @@ TEST_F(OverviewButtonTrayTest, TabletModeObserverOnTabletModeToggled) {
   TabletModeControllerTestApi().EnterTabletMode();
   EXPECT_TRUE(GetTray()->visible());
 
-  TabletModeControllerTestApi().LeaveTabletMode();
+  TabletModeControllerTestApi().LeaveTabletMode(false);
   EXPECT_FALSE(GetTray()->visible());
 }
 
@@ -302,7 +302,7 @@ TEST_F(OverviewButtonTrayTest, VisibilityChangesForSystemModalWindow) {
   ASSERT_TRUE(Shell::IsSystemModalWindowOpen());
   TabletModeControllerTestApi().EnterTabletMode();
   EXPECT_TRUE(GetTray()->visible());
-  TabletModeControllerTestApi().LeaveTabletMode();
+  TabletModeControllerTestApi().LeaveTabletMode(false);
   EXPECT_FALSE(GetTray()->visible());
 }
 

ash/wm/tablet_mode/tablet_mode_controller.h

@@ -164,12 +164,17 @@ class ASH_EXPORT TabletModeController
   // a certain range of time before using unstable angle.
   bool CanUseUnstableLidAngle() const;
 
-  // Attempts to enter tablet mode and update the internal keyboard and
-  // touchpad.
+  // True if it is possible to enter tablet mode in the current
+  // configuration. If this returns false, it should never be the case that
+  // tablet mode becomes enabled.
+  bool CanEnterTabletMode();
+
+  // Attempts to enter tablet mode and locks the internal keyboard and touchpad.
   void AttemptEnterTabletMode();
 
-  // Attempts to exit tablet mode and update the internal keyboard and touchpad.
-  void AttemptLeaveTabletMode();
+  // Attempts to exit tablet mode and unlocks the internal keyboard and touchpad
+  // if |called_by_device_update| is false.
+  void AttemptLeaveTabletMode(bool called_by_device_update);
 
   // Record UMA stats tracking TabletMode usage. If |type| is
   // TABLET_MODE_INTERVAL_INACTIVE, then record that TabletMode has been
@@ -198,17 +203,6 @@ class ASH_EXPORT TabletModeController
   // sent from device manager. This will exit tablet mode if needed.
   void HandleMouseAddedOrRemoved();
 
-  // Update the internal mouse and keyboard event blocker |event_blocker_|
-  // according to current configuration. The internal input events should be
-  // blocked if 1) we are currently in tablet mode or 2) we are currently in
-  // laptop mode but the lid is flipped over (i.e., we are in laptop mode
-  // because of an external attached mouse).
-  void UpdateInternalMouseAndKeyboardEventBlocker();
-
-  // Returns true if the current lid angle can be detected and is in tablet mode
-  // angle range.
-  bool LidAngleIsInTabletModeRange();
-
   // Callback function for |bluetooth_devices_observer_|. Called when |device|
   // changes.
   void UpdateBluetoothDevice(device::BluetoothDevice* device);
@@ -220,6 +214,9 @@ class ASH_EXPORT TabletModeController
   // internal keyboard and touchpad.
   std::unique_ptr<ScopedDisableInternalMouseAndKeyboard> event_blocker_;
 
+  // Whether we have ever seen accelerometer data.
+  bool have_seen_accelerometer_data_ = false;
+
   // Whether the lid angle can be detected. If it's true, the device is a
   // convertible device (both screen acclerometer and keyboard acclerometer are
   // available, thus lid angle is detectable). And if it's false, the device is

ash/wm/tablet_mode/tablet_mode_controller_test_api.cc

@@ -21,8 +21,9 @@ void TabletModeControllerTestApi::EnterTabletMode() {
   tablet_mode_controller_->AttemptEnterTabletMode();
 }
 
-void TabletModeControllerTestApi::LeaveTabletMode() {
-  tablet_mode_controller_->AttemptLeaveTabletMode();
+void TabletModeControllerTestApi::LeaveTabletMode(
+    bool called_by_device_update) {
+  tablet_mode_controller_->AttemptLeaveTabletMode(called_by_device_update);
 }
 
 void TabletModeControllerTestApi::AttachExternalMouse() {

ash/wm/tablet_mode/tablet_mode_controller_test_api.h

@@ -26,9 +26,10 @@ class TabletModeControllerTestApi {
   TabletModeControllerTestApi();
   ~TabletModeControllerTestApi();
 
-  // Enters or exits tablet mode.
+  // Enters or exits tablet mode. Use these instead when stuff such as tray
+  // visibilty depends on the event blocker instead of the actual tablet mode.
   void EnterTabletMode();
-  void LeaveTabletMode();
+  void LeaveTabletMode(bool called_by_device_update);
 
   // Called to attach an external mouse. If we're currently in tablet mode,
   // tablet mode will be ended because of this.