ime: Mark IMEBridge initialization and usage as Chrome OS only.

IMEBridge is only ever initialized for Chrome OS [1], so all usages of
IMEBridge::Get() will return nullptr for other platforms.

Mark those functions as Chrome OS only, and (re)move any usages that
appear in other platforms.

A followup patch will move IMEBridge to ui/base/ime/chromeos.

[1] https://source.chromium.org/search?q=IMEBridge::Initialize&sq=&ss=chromium%2Fchromium%2Fsrc&originalUrl=https:%2F%2Fcs.chromium.org%2F

Bug: 1083803
Change-Id: Ic9cb463a918ef990dfff5ef29e311b3fbfb664b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2212198Reviewed-by: Keith Lee <keithlee@chromium.org>
Commit-Queue: Darren Shen <shend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772136}

ui/base/ime/chromeos/input_method_chromeos.cc

@@ -289,6 +289,20 @@ InputMethodChromeOS::GetInputMethodKeyboardController() {
   return InputMethodBase::GetInputMethodKeyboardController();
 }
 
+void InputMethodChromeOS::OnFocus() {
+  ui::IMEBridge* bridge = ui::IMEBridge::Get();
+  if (bridge) {
+    bridge->SetInputContextHandler(this);
+    bridge->MaybeSwitchEngine();
+  }
+}
+
+void InputMethodChromeOS::OnBlur() {
+  if (ui::IMEBridge::Get() &&
+      ui::IMEBridge::Get()->GetInputContextHandler() == this)
+    ui::IMEBridge::Get()->SetInputContextHandler(nullptr);
+}
+
 void InputMethodChromeOS::OnWillChangeFocusedClient(
     TextInputClient* focused_before,
     TextInputClient* focused) {

ui/base/ime/chromeos/input_method_chromeos.h

@@ -44,6 +44,8 @@ class COMPONENT_EXPORT(UI_BASE_IME_CHROMEOS) InputMethodChromeOS
   InputMethodKeyboardController* GetInputMethodKeyboardController() override;
 
   // Overridden from InputMethodBase:
+  void OnFocus() override;
+  void OnBlur() override;
   void OnWillChangeFocusedClient(TextInputClient* focused_before,
                                  TextInputClient* focused) override;
   void OnDidChangeFocusedClient(TextInputClient* focused_before,

ui/base/ime/ime_bridge.cc

@@ -13,7 +13,9 @@
 
 namespace ui {
 
+#if defined(OS_CHROMEOS)
 static IMEBridge* g_ime_bridge = nullptr;
+#endif
 
 // An implementation of IMEBridge.
 class IMEBridgeImpl : public IMEBridge {
@@ -126,6 +128,7 @@ IMEBridge::IMEBridge() {}
 
 IMEBridge::~IMEBridge() {}
 
+#if defined(OS_CHROMEOS)
 // static.
 void IMEBridge::Initialize() {
   if (!g_ime_bridge)
@@ -142,5 +145,6 @@ void IMEBridge::Shutdown() {
 IMEBridge* IMEBridge::Get() {
   return g_ime_bridge;
 }
+#endif
 
 }  // namespace ui

ui/base/ime/ime_bridge.h

@@ -30,6 +30,7 @@ class COMPONENT_EXPORT(UI_BASE_IME) IMEBridge {
  public:
   virtual ~IMEBridge();
 
+#if defined(OS_CHROMEOS)
   // Allocates the global instance. Must be called before any calls to Get().
   static void Initialize();
 
@@ -38,6 +39,7 @@ class COMPONENT_EXPORT(UI_BASE_IME) IMEBridge {
 
   // Returns IMEBridge global instance. Initialize() must be called first.
   static IMEBridge* Get();
+#endif
 
   // Returns current InputContextHandler. This function returns NULL if input
   // context is not ready to use.

ui/base/ime/input_method_base.cc

@@ -9,7 +9,6 @@
 #include "base/check.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
-#include "ui/base/ime/ime_bridge.h"
 #include "ui/base/ime/input_method_delegate.h"
 #include "ui/base/ime/input_method_keyboard_controller_stub.h"
 #include "ui/base/ime/input_method_observer.h"
@@ -30,9 +29,6 @@ InputMethodBase::InputMethodBase(
 InputMethodBase::~InputMethodBase() {
   for (InputMethodObserver& observer : observer_list_)
     observer.OnInputMethodDestroyed(this);
-  if (ui::IMEBridge::Get() &&
-      ui::IMEBridge::Get()->GetInputContextHandler() == this)
-    ui::IMEBridge::Get()->SetInputContextHandler(nullptr);
 }
 
 void InputMethodBase::SetDelegate(internal::InputMethodDelegate* delegate) {
@@ -40,17 +36,9 @@ void InputMethodBase::SetDelegate(internal::InputMethodDelegate* delegate) {
 }
 
 void InputMethodBase::OnFocus() {
-  ui::IMEBridge* bridge = ui::IMEBridge::Get();
-  if (bridge) {
-    bridge->SetInputContextHandler(this);
-    bridge->MaybeSwitchEngine();
-  }
 }
 
 void InputMethodBase::OnBlur() {
-  if (ui::IMEBridge::Get() &&
-      ui::IMEBridge::Get()->GetInputContextHandler() == this)
-    ui::IMEBridge::Get()->SetInputContextHandler(nullptr);
 }
 
 #if defined(OS_WIN)

ui/base/ime/linux/input_method_auralinux.cc

@@ -8,8 +8,6 @@
 #include "base/bind.h"
 #include "base/environment.h"
 #include "ui/base/ime/constants.h"
-#include "ui/base/ime/ime_bridge.h"
-#include "ui/base/ime/ime_engine_handler_interface.h"
 #include "ui/base/ime/linux/linux_input_method_context_factory.h"
 #include "ui/base/ime/text_input_client.h"
 #include "ui/events/event.h"
@@ -215,14 +213,6 @@ void InputMethodAuraLinux::UpdateContextFocusState() {
     context_simple_->Focus();
   else
     context_simple_->Blur();
-
-  if (!ui::IMEBridge::Get())  // IMEBridge could be null for tests.
-    return;
-
-  ui::IMEEngineHandlerInterface::InputContext context(
-      GetTextInputType(), GetTextInputMode(), GetTextInputFlags(),
-      ui::TextInputClient::FOCUS_REASON_OTHER, GetClientShouldDoLearning());
-  ui::IMEBridge::Get()->SetCurrentInputContext(context);
 }
 
 void InputMethodAuraLinux::OnTextInputTypeChanged(

ui/base/ime/win/input_method_win_base.cc

@@ -14,7 +14,6 @@
 #include "base/memory/ptr_util.h"
 #include "base/win/windows_version.h"
 #include "ui/base/ime/ime_bridge.h"
-#include "ui/base/ime/ime_engine_handler_interface.h"
 #include "ui/base/ime/text_input_client.h"
 #include "ui/base/ime/win/on_screen_keyboard_display_manager_input_pane.h"
 #include "ui/base/ime/win/on_screen_keyboard_display_manager_tab_tip.h"
@@ -491,14 +490,4 @@ ui::EventDispatchDetails InputMethodWinBase::ProcessUnhandledKeyEvent(
   return details;
 }
 
-void InputMethodWinBase::UpdateEngineFocusAndInputContext() {
-  if (!ui::IMEBridge::Get())  // IMEBridge could be null for tests.
-    return;
-
-  ui::IMEEngineHandlerInterface::InputContext context(
-      GetTextInputType(), GetTextInputMode(), GetTextInputFlags(),
-      ui::TextInputClient::FOCUS_REASON_OTHER, GetClientShouldDoLearning());
-  ui::IMEBridge::Get()->SetCurrentInputContext(context);
-}
-
 }  // namespace ui

ui/base/ime/win/input_method_win_base.h

@@ -62,10 +62,6 @@ class COMPONENT_EXPORT(UI_BASE_IME_WIN) InputMethodWinBase
       ui::KeyEvent* event,
       const std::vector<MSG>* char_msgs);
 
-  // Update focus state for Chromium IME extension and update input context in
-  // ui::IMEBridge.
-  void UpdateEngineFocusAndInputContext();
-
   // The toplevel window handle.
   const HWND toplevel_window_handle_;
 

ui/base/ime/win/input_method_win_imm32.cc

@@ -12,8 +12,6 @@
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/metrics/histogram_macros.h"
-#include "ui/base/ime/ime_bridge.h"
-#include "ui/base/ime/ime_engine_handler_interface.h"
 #include "ui/base/ime/text_input_client.h"
 #include "ui/base/ime/win/tsf_input_scope.h"
 #include "ui/display/win/screen_win.h"
@@ -348,8 +346,6 @@ void InputMethodWinImm32::UpdateIMEState() {
   imm32_manager_.SetTextInputMode(window_handle, text_input_mode);
   tsf_inputscope::SetInputScopeForTsfUnawareWindow(
       window_handle, text_input_type, text_input_mode);
-
-  InputMethodWinBase::UpdateEngineFocusAndInputContext();
 }
 
 }  // namespace ui

ui/base/ime/win/input_method_win_tsf.cc

@@ -100,7 +100,6 @@ void InputMethodWinTSF::OnTextInputTypeChanged(const TextInputClient* client) {
   }
   ui::TSFBridge::GetInstance()->CancelComposition();
   ui::TSFBridge::GetInstance()->OnTextInputTypeChanged(client);
-  InputMethodWinBase::UpdateEngineFocusAndInputContext();
 }
 
 void InputMethodWinTSF::OnCaretBoundsChanged(const TextInputClient* client) {