[Gin] Add V8NoTurbo experiment to disable Ignition+TurboFan.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/about_flags.h"
 
 #include <iterator>
 #include <map>
 #include <set>
 #include <utility>
@@ skipping 874 matching lines @@
      FEATURE_VALUE_TYPE(features::kAsmJsToWebAssembly)},
     {"enable-webassembly", IDS_FLAGS_ENABLE_WASM_NAME,
      IDS_FLAGS_ENABLE_WASM_DESCRIPTION, kOsAll,
      FEATURE_VALUE_TYPE(features::kWebAssembly)},
     {"shared-array-buffer", IDS_FLAGS_ENABLE_SHARED_ARRAY_BUFFER_NAME,
      IDS_FLAGS_ENABLE_SHARED_ARRAY_BUFFER_DESCRIPTION, kOsAll,
      FEATURE_VALUE_TYPE(features::kSharedArrayBuffer)},
     {"enable-v8-future", IDS_FLAGS_V8_FUTURE_NAME,
      IDS_FLAGS_V8_FUTURE_DESCRIPTION, kOsAll,
      FEATURE_VALUE_TYPE(features::kV8Future)},
+    {"disable-v8-ignition-turbo", IDS_FLAGS_V8_DISABLE_IGNITION_TURBO_NAME,
+     IDS_FLAGS_V8_DISABLE_IGNITION_TURBO_DESCRIPTION, kOsAll,
+     FEATURE_VALUE_TYPE(features::kV8NoTurbo)},
     {"disable-software-rasterizer", IDS_FLAGS_SOFTWARE_RASTERIZER_NAME,
      IDS_FLAGS_SOFTWARE_RASTERIZER_DESCRIPTION,
 #if BUILDFLAG(ENABLE_SWIFTSHADER)
      kOsAll,
 #else   // BUILDFLAG(ENABLE_SWIFTSHADER)
      0,
 #endif  // BUILDFLAG(ENABLE_SWIFTSHADER)
      SINGLE_DISABLE_VALUE_TYPE(switches::kDisableSoftwareRasterizer)},
     {"enable-gpu-rasterization", IDS_FLAGS_GPU_RASTERIZATION_NAME,
      IDS_FLAGS_GPU_RASTERIZATION_DESCRIPTION, kOsAll,
@@ skipping 1623 matching lines @@
 const base::HistogramBase::Sample kBadSwitchFormatHistogramId = 0;
 
 const FeatureEntry* GetFeatureEntries(size_t* count) {
   *count = arraysize(kFeatureEntries);
   return kFeatureEntries;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags