From a954d2cfd4e683be79888e7f1f92de8413c65278 Mon Sep 17 00:00:00 2001
From: Matan Lurey <matanlurey@users.noreply.github.com>
Date: Wed, 13 Mar 2024 22:13:29 -0700
Subject: [PATCH] Remove `--enable-impeller-{backend}` flags (always `True`).
 (flutter/engine#51402)

Closes https://github.com/flutter/flutter/issues/142725.
---
 engine/src/flutter/ci/builders/local_engine.json   |  8 +-------
 .../src/flutter/ci/builders/mac_host_engine.json   |  3 ---
 .../impeller/docs/android_validation_layers.md     |  1 -
 .../impeller/docs/renderdoc_frame_capture.md       |  9 +++++----
 engine/src/flutter/tools/gn                        | 14 --------------
 5 files changed, 6 insertions(+), 29 deletions(-)

diff --git a/engine/src/flutter/ci/builders/local_engine.json b/engine/src/flutter/ci/builders/local_engine.json
index 078bebb55d8..2237511bed6 100644
--- a/engine/src/flutter/ci/builders/local_engine.json
+++ b/engine/src/flutter/ci/builders/local_engine.json
@@ -11,7 +11,6 @@
         "--android",
         "--android-cpu=arm64",
         "--no-stripped",
-        "--enable-impeller-vulkan",
         "--no-lto"
       ],
       "name": "android_debug_arm64",
@@ -31,7 +30,6 @@
         "--android",
         "--android-cpu=arm64",
         "--no-stripped",
-        "--enable-impeller-vulkan",
         "--no-lto"
       ],
       "name": "android_profile_arm64",
@@ -51,7 +49,6 @@
         "--android",
         "--android-cpu=arm64",
         "--no-stripped",
-        "--enable-impeller-vulkan",
         "--no-lto"
       ],
       "name": "android_release_arm64",
@@ -69,7 +66,6 @@
         "--runtime-mode",
         "debug",
         "--no-stripped",
-        "--enable-impeller-vulkan",
         "--no-lto"
       ],
       "name": "host_debug",
@@ -87,7 +83,6 @@
         "--runtime-mode",
         "profile",
         "--no-stripped",
-        "--enable-impeller-vulkan",
         "--no-lto"
       ],
       "name": "host_profile",
@@ -105,7 +100,6 @@
         "--runtime-mode",
         "release",
         "--no-stripped",
-        "--enable-impeller-vulkan",
         "--no-lto"
       ],
       "name": "host_release",
@@ -115,4 +109,4 @@
       }
     }
   ]
-}
\ No newline at end of file
+}
diff --git a/engine/src/flutter/ci/builders/mac_host_engine.json b/engine/src/flutter/ci/builders/mac_host_engine.json
index 8998f67ac92..c12a0632a13 100644
--- a/engine/src/flutter/ci/builders/mac_host_engine.json
+++ b/engine/src/flutter/ci/builders/mac_host_engine.json
@@ -28,7 +28,6 @@
                 "--no-lto",
                 "--prebuilt-dart-sdk",
                 "--build-embedder-examples",
-                "--enable-impeller-vulkan",
                 "--use-glfw-swiftshader"
             ],
             "name": "host_debug",
@@ -158,8 +157,6 @@
                 "--no-lto",
                 "--prebuilt-dart-sdk",
                 "--build-embedder-examples",
-                "--enable-impeller-vulkan",
-                "--enable-impeller-opengles",
                 "--use-glfw-swiftshader"
             ],
             "name": "host_release",
diff --git a/engine/src/flutter/impeller/docs/android_validation_layers.md b/engine/src/flutter/impeller/docs/android_validation_layers.md
index 55ada1d4695..ae32076c686 100644
--- a/engine/src/flutter/impeller/docs/android_validation_layers.md
+++ b/engine/src/flutter/impeller/docs/android_validation_layers.md
@@ -9,7 +9,6 @@ Example:
 ```sh
 flutter/tools/gn \
   --runtime-mode=debug \
-  --enable-impeller-vulkan \
   --enable-vulkan-validation-layers \
   --no-lto \
   --unoptimized \
diff --git a/engine/src/flutter/impeller/docs/renderdoc_frame_capture.md b/engine/src/flutter/impeller/docs/renderdoc_frame_capture.md
index aad8739d52c..247ec7eaf60 100644
--- a/engine/src/flutter/impeller/docs/renderdoc_frame_capture.md
+++ b/engine/src/flutter/impeller/docs/renderdoc_frame_capture.md
@@ -8,7 +8,7 @@
 ```bash
 # In your $ENGINE_SRC folder, do:
 
-./flutter/tools/gn --unopt --enable-impeller-vulkan
+./flutter/tools/gn --unopt
 ninja -C out/host_debug_unopt/
 ```
 
@@ -17,9 +17,10 @@ ninja -C out/host_debug_unopt/
 ![Launch App](assets/renderdoc_frame_capture/launch-app.png)
 
 4. Fill out the following parameters, and click launch:
-  - executable: `$ENGINE_SRC/out/host_debug_impeller_vulkan/impeller_unittests` (expand `ENGINE_SRC`).
-  - args: `--gtest_filter="*CanDrawRect/Vulkan*" --enable_playground`
-  - working dir: `$ENGINE_SRC` (expand `ENGINE_SRC`)
+
+- executable: `$ENGINE_SRC/out/host_debug_impeller_vulkan/impeller_unittests` (expand `ENGINE_SRC`).
+- args: `--gtest_filter="*CanDrawRect/Vulkan*" --enable_playground`
+- working dir: `$ENGINE_SRC` (expand `ENGINE_SRC`)
 
 5. For the frame you wish to capture, press `F12`, you will now be able to see the frame capture and inspect the state.
 
diff --git a/engine/src/flutter/tools/gn b/engine/src/flutter/tools/gn
index 9625e832ef1..ff2281bfb7a 100755
--- a/engine/src/flutter/tools/gn
+++ b/engine/src/flutter/tools/gn
@@ -1237,20 +1237,6 @@ def parse_args(args):
   )
 
   # Impeller flags.
-  parser.add_argument(
-      '--enable-impeller-vulkan',
-      default=True,
-      action='store_true',
-      help='Enable the Impeller Vulkan backend.'
-  )
-
-  parser.add_argument(
-      '--enable-impeller-opengles',
-      default=True,
-      action='store_true',
-      help='Enable the Impeller OpenGL ES backend.'
-  )
-
   parser.add_argument(
       '--prebuilt-impellerc',
       default=None,