Revert "[Impeller] Added a switch to turn on vulkan (#42585)"

This reverts commit f5007e9.

Author: zanderso

common/settings.h

@@ -217,9 +217,6 @@ struct Settings {
   bool enable_impeller = false;
 #endif
 
-  // Requests a particular backend to be used (ex "opengles" or "vulkan")
-  std::optional<std::string> impeller_backend;
-
   // Enable Vulkan validation on backends that support it. The validation layers
   // must be available to the application.
   bool enable_vulkan_validation = false;

shell/common/switches.cc

@@ -443,23 +443,11 @@ Settings SettingsFromCommandLine(const fml::CommandLine& command_line) {
   settings.use_asset_fonts =
       !command_line.HasOption(FlagForSwitch(Switch::DisableAssetFonts));
 
-  {
-    std::string enable_impeller_value;
-    if (command_line.GetOptionValue(FlagForSwitch(Switch::EnableImpeller),
-                                    &enable_impeller_value)) {
-      settings.enable_impeller =
-          enable_impeller_value.empty() || "true" == enable_impeller_value;
-    }
-  }
-
-  {
-    std::string impeller_backend_value;
-    if (command_line.GetOptionValue(FlagForSwitch(Switch::ImpellerBackend),
-                                    &impeller_backend_value)) {
-      if (!impeller_backend_value.empty()) {
-        settings.impeller_backend = impeller_backend_value;
-      }
-    }
+  std::string enable_impeller_value;
+  if (command_line.GetOptionValue(FlagForSwitch(Switch::EnableImpeller),
+                                  &enable_impeller_value)) {
+    settings.enable_impeller =
+        enable_impeller_value.empty() || "true" == enable_impeller_value;
   }
 
   settings.enable_vulkan_validation =

shell/common/switches.h

@@ -261,10 +261,6 @@ DEF_SWITCH(EnableImpeller,
            "enable-impeller",
            "Enable the Impeller renderer on supported platforms. Ignored if "
            "Impeller is not supported on the platform.")
-DEF_SWITCH(ImpellerBackend,
-           "impeller-backend",
-           "Requests a particular Impeller backend on platforms that support "
-           "multiple backends. (ex `opengles` or `vulkan`)")
 DEF_SWITCH(EnableVulkanValidation,
            "enable-vulkan-validation",
            "Enable loading Vulkan validation layers. The layers must be "

shell/platform/android/android_context_gl_impeller.cc

@@ -74,7 +74,7 @@ static std::shared_ptr<impeller::Context> CreateImpellerContext(
     FML_LOG(ERROR) << "Could not add reactor worker.";
     return nullptr;
   }
-  FML_LOG(ERROR) << "Using the Impeller rendering backend (OpenGLES).";
+  FML_LOG(ERROR) << "Using the Impeller rendering backend.";
   return context;
 }
 

shell/platform/android/android_context_vulkan_impeller.cc

@@ -34,9 +34,6 @@ static std::shared_ptr<impeller::Context> CreateImpellerContext(
   settings.cache_directory = fml::paths::GetCachesDirectory();
   settings.worker_task_runner = std::move(worker_task_runner);
   settings.enable_validation = enable_vulkan_validation;
-
-  FML_LOG(ERROR) << "Using the Impeller rendering backend (Vulkan).";
-
   return impeller::ContextVK::Create(std::move(settings));
 }
 

shell/platform/android/io/flutter/embedding/engine/loader/FlutterLoader.java

@@ -41,8 +41,6 @@ public class FlutterLoader {
       "io.flutter.embedding.android.OldGenHeapSize";
   private static final String ENABLE_IMPELLER_META_DATA_KEY =
       "io.flutter.embedding.android.EnableImpeller";
-  private static final String IMPELLER_BACKEND_META_DATA_KEY =
-      "io.flutter.embedding.android.ImpellerBackend";
 
   /**
    * Set whether leave or clean up the VM after the last shell shuts down. It can be set from app's
@@ -318,12 +316,8 @@ public void ensureInitializationComplete(
 
       shellArgs.add("--prefetched-default-font-manager");
 
-      if (metaData != null) {
-        if (metaData.getBoolean(ENABLE_IMPELLER_META_DATA_KEY, false)) {
-          shellArgs.add("--enable-impeller");
-        }
-        String backend = metaData.getString(IMPELLER_BACKEND_META_DATA_KEY, "opengles");
-        shellArgs.add("--impeller-backend=" + backend);
+      if (metaData != null && metaData.getBoolean(ENABLE_IMPELLER_META_DATA_KEY, false)) {
+        shellArgs.add("--enable-impeller");
       }
 
       final String leakVM = isLeakVM(metaData) ? "true" : "false";

shell/platform/android/platform_view_android.cc

@@ -51,9 +51,16 @@ std::unique_ptr<AndroidSurface> AndroidSurfaceFactoryImpl::CreateSurface() {
       }
     case AndroidRenderingAPI::kVulkan:
       FML_DCHECK(enable_impeller_);
-      return std::make_unique<AndroidSurfaceVulkanImpeller>(
+      // TODO(kaushikiska@): Enable this after wiring a preference for Vulkan
+      // backend.
+#if false
+    return std::make_unique<AndroidSurfaceVulkanImpeller>(
           std::static_pointer_cast<AndroidContextVulkanImpeller>(
               android_context_));
+#else
+      return std::make_unique<AndroidSurfaceGLImpeller>(
+          std::static_pointer_cast<AndroidContextGLImpeller>(android_context_));
+#endif
     default:
       FML_DCHECK(false);
       return nullptr;
@@ -66,36 +73,19 @@ static std::shared_ptr<flutter::AndroidContext> CreateAndroidContext(
     const std::shared_ptr<fml::ConcurrentTaskRunner>& worker_task_runner,
     uint8_t msaa_samples,
     bool enable_impeller,
-    const std::optional<std::string>& impeller_backend,
     bool enable_vulkan_validation) {
   if (use_software_rendering) {
     return std::make_shared<AndroidContext>(AndroidRenderingAPI::kSoftware);
   }
   if (enable_impeller) {
-    // TODO(gaaclarke): We need to devise a more complete heuristic about what
-    //                  backend to use by default.
-    // Default value is OpenGLES.
-    AndroidRenderingAPI backend = AndroidRenderingAPI::kOpenGLES;
-    if (impeller_backend.has_value()) {
-      if (impeller_backend.value() == "opengles") {
-        backend = AndroidRenderingAPI::kOpenGLES;
-      } else if (impeller_backend.value() == "vulkan") {
-        backend = AndroidRenderingAPI::kVulkan;
-      } else {
-        FML_CHECK(impeller_backend.value() == "vulkan" ||
-                  impeller_backend.value() == "opengles");
-      }
-    }
-    switch (backend) {
-      case AndroidRenderingAPI::kOpenGLES:
-        return std::make_unique<AndroidContextGLImpeller>(
-            std::make_unique<impeller::egl::Display>());
-      case AndroidRenderingAPI::kVulkan:
-        return std::make_unique<AndroidContextVulkanImpeller>(
-            enable_vulkan_validation, worker_task_runner);
-      default:
-        FML_UNREACHABLE();
-    }
+    // TODO(kaushikiska@): Enable this after wiring a preference for Vulkan
+    // backend.
+#if false
+    return std::make_unique<AndroidContextVulkanImpeller>(enable_vulkan_validation, std::move(worker_task_runner));
+#else
+    return std::make_unique<AndroidContextGLImpeller>(
+        std::make_unique<impeller::egl::Display>());
+#endif
   }
   return std::make_unique<AndroidContextGLSkia>(
       AndroidRenderingAPI::kOpenGLES,               //
@@ -122,7 +112,6 @@ PlatformViewAndroid::PlatformViewAndroid(
               worker_task_runner,
               msaa_samples,
               delegate.OnPlatformViewGetSettings().enable_impeller,
-              delegate.OnPlatformViewGetSettings().impeller_backend,
               delegate.OnPlatformViewGetSettings().enable_vulkan_validation)) {}
 
 PlatformViewAndroid::PlatformViewAndroid(