Revert "Add RestartEngine API to handle cold-restart scenario"

This reverts commit 330072d.

Author: bwikbs

shell/platform/tizen/channels/platform_view_channel.cc

@@ -80,10 +80,6 @@ void PlatformViewChannel::ClearViewFactories() {
   view_factories_.clear();
 }
 
-void PlatformViewChannel::PreEngineRestart() {
-  ClearViewInstances();
-}
-
 void PlatformViewChannel::SendKeyEvent(Ecore_Event_Key* key, bool is_down) {
   auto instances = ViewInstances();
   auto it = instances.find(CurrentFocusedViewId());

shell/platform/tizen/channels/platform_view_channel.h

@@ -38,8 +38,6 @@ class PlatformViewChannel {
   void DispatchCompositionUpdateEvent(const std::string& key);
   void DispatchCompositionEndEvent(const std::string& key);
 
-  void PreEngineRestart();
-
  private:
   void HandleMethodCall(
       const flutter::MethodCall<flutter::EncodableValue>& call,

shell/platform/tizen/flutter_tizen_engine.cc

@@ -194,12 +194,6 @@ bool FlutterTizenEngine::RunEngine(
         auto engine = reinterpret_cast<FlutterTizenEngine*>(user_data);
         auto message = engine->ConvertToDesktopMessage(*engine_message);
         engine->message_dispatcher->HandleMessage(message);
-
-        // Workarounds for handling engine restarts. Needs to be replaced by
-        // PlatformView::OnPreEngineRestart.
-        if (strncmp(message.channel, "flutter/isolate", 15) == 0) {
-          engine->RestartEngine();
-        }
       };
   args.custom_task_runners = &custom_task_runners;
 #ifndef TIZEN_RENDERER_EVAS_GL
@@ -276,13 +270,6 @@ bool FlutterTizenEngine::StopEngine() {
   return false;
 }
 
-void FlutterTizenEngine::RestartEngine() {
-  // Need to reset native resource.
-  if (platform_view_channel) {
-    platform_view_channel->PreEngineRestart();
-  }
-}
-
 FlutterDesktopPluginRegistrarRef FlutterTizenEngine::GetPluginRegistrar() {
   return plugin_registrar_.get();
 }

shell/platform/tizen/flutter_tizen_engine.h

@@ -70,8 +70,6 @@ class FlutterTizenEngine : public TizenRenderer::Delegate {
   bool RunEngine(const FlutterDesktopEngineProperties& engine_properties);
   bool StopEngine();
 
-  void RestartEngine();
-
   // Returns the currently configured Plugin Registrar.
   FlutterDesktopPluginRegistrarRef GetPluginRegistrar();