[power] Clean up PowerScheduler experiment infrastructure

This change removes the code for the PowerScheduler feature and all
related earlier experiments for Chrome and WebView.

Bug: 1166695,b/214586482
Change-Id: Iadb5a3c1591e648734e84e0df600a876000d8007
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3533415
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Ken Rockot <rockot@google.com>
Reviewed-by: Weilun Shi <sweilun@chromium.org>
Commit-Queue: Oksana Zhuravlova <oksamyt@chromium.org>
Cr-Commit-Position: refs/heads/main@{#984574}

android_webview/BUILD.gn

@@ -844,7 +844,6 @@ android_library("common_java") {
     "//components/feature_engagement/public:public_java",
     "//components/metrics:metrics_java",
     "//components/network_session_configurator/android:network_session_configurator_java",
-    "//components/power_scheduler:power_scheduler_java",
     "//components/viz:viz_java",
     "//components/webrtc:components_webrtc_java",
     "//content/public/android:content_java",

android_webview/java/src/org/chromium/android_webview/common/ProductionSupportedFlagList.java

@@ -11,7 +11,6 @@
 import org.chromium.components.feature_engagement.FeatureConstants;
 import org.chromium.components.metrics.MetricsSwitches;
 import org.chromium.components.network_session_configurator.NetworkSessionSwitches;
-import org.chromium.components.power_scheduler.PowerSchedulerFeatures;
 import org.chromium.components.viz.common.VizFeatures;
 import org.chromium.components.webrtc.ComponentsWebRtcFeatures;
 import org.chromium.content_public.common.ContentFeatures;
@@ -127,20 +126,6 @@ private ProductionSupportedFlagList() {}
                             + "feature flag until the true runtime cost can be measured."),
             Flag.baseFeature(AwFeatures.WEBVIEW_DISPLAY_CUTOUT,
                     "Enables display cutout (notch) support in WebView for Android P and above."),
-            Flag.baseFeature(PowerSchedulerFeatures.WEBVIEW_CPU_AFFINITY_RESTRICT_TO_LITTLE_CORES,
-                    "Forces WebView to do rendering work on LITTLE CPU cores on big.LITTLE "
-                            + "architectures"),
-            Flag.baseFeature(PowerSchedulerFeatures.WEBVIEW_POWER_SCHEDULER_THROTTLE_IDLE,
-                    "Restricts all of WebView's out-of-process renderer threads to use only LITTLE "
-                            + "CPU cores on big.LITTLE architectures when the power mode is idle. "
-                            + "WebViewCpuAffinityRestrictToLittleCores, if set, takes precedence "
-                            + "over this flag."),
-            Flag.baseFeature(PowerSchedulerFeatures.POWER_SCHEDULER,
-                    "Enables the Power Scheduler. Defaults to throttling when idle or in no-op "
-                            + "animations, if at least 250ms of CPU time were spent "
-                            + "in the first 500ms after entering idle/no-op animation mode. "
-                            + "Can be further configured via field trial parameters, "
-                            + "see power_scheduler.h/cc for details."),
             Flag.baseFeature(BlinkFeatures.WEBVIEW_ACCELERATE_SMALL_CANVASES,
                     "Accelerate all canvases in webview."),
             Flag.baseFeature(AwFeatures.WEBVIEW_MIXED_CONTENT_AUTOUPGRADES,

android_webview/lib/aw_main_delegate.cc

@@ -41,12 +41,11 @@
 #include "components/crash/core/common/crash_key.h"
 #include "components/gwp_asan/buildflags/buildflags.h"
 #include "components/metrics/unsent_log_store_metrics.h"
-#include "components/power_scheduler/power_scheduler.h"
 #include "components/safe_browsing/android/safe_browsing_api_handler_bridge.h"
 #include "components/services/heap_profiling/public/cpp/profiling_client.h"
 #include "components/spellcheck/spellcheck_buildflags.h"
-#include "components/variations/variations_ids_provider.h"
 #include "components/translate/core/common/translate_util.h"
+#include "components/variations/variations_ids_provider.h"
 #include "components/version_info/android/channel_getter.h"
 #include "components/viz/common/features.h"
 #include "content/public/browser/android/media_url_interceptor_register.h"
@@ -397,15 +396,7 @@ void AwMainDelegate::PostFieldTrialInitialization() {
       *base::CommandLine::ForCurrentProcess();
   std::string process_type =
       command_line.GetSwitchValueASCII(switches::kProcessType);
-  bool is_browser_process = process_type.empty();
-
-  // Enable LITTLE-cores only mode/idle power mode throttling if the features
-  // are enabled, but only for child processes, as the browser process is shared
-  // with the hosting app.
-  if (!is_browser_process) {
-    power_scheduler::PowerScheduler::GetInstance()
-        ->InitializePolicyFromFeatureList();
-  }
+  [[maybe_unused]] bool is_browser_process = process_type.empty();
 
 #if BUILDFLAG(ENABLE_GWP_ASAN_MALLOC)
   gwp_asan::EnableForMalloc(is_canary_dev || is_browser_process,

android_webview/renderer/aw_render_thread_observer.cc

@@ -4,7 +4,6 @@
 
 #include "android_webview/renderer/aw_render_thread_observer.h"
 
-#include "components/power_scheduler/power_scheduler.h"
 #include "third_party/blink/public/common/associated_interfaces/associated_interface_registry.h"
 #include "third_party/blink/public/platform/web_cache.h"
 #include "third_party/blink/public/platform/web_network_state_notifier.h"

chrome/app/chrome_main_delegate.cc

@@ -144,7 +144,6 @@
 #include "chrome/browser/flags/android/chrome_feature_list.h"
 #include "chrome/common/chrome_descriptors.h"
 #include "components/crash/android/pure_java_exception_handler.h"
-#include "components/power_scheduler/power_scheduler.h"
 #include "net/android/network_change_notifier_factory_android.h"
 #else  // BUILDFLAG(IS_ANDROID)
 // Diagnostics is only available on non-android platforms.
@@ -655,14 +654,6 @@ void ChromeMainDelegate::PostFieldTrialInitialization() {
   // it if not already overridden by command line, field trial etc.
   net::HttpCache::SplitCacheFeatureEnableByDefault();
 
-#if BUILDFLAG(IS_ANDROID)
-  // For child processes, this requires allowlisting of the sched_setaffinity()
-  // syscall in the sandbox (baseline_policy_android.cc). When this call is
-  // removed, the sandbox allowlist should be updated too.
-  power_scheduler::PowerScheduler::GetInstance()
-      ->InitializePolicyFromFeatureList();
-#endif
-
 #if BUILDFLAG(IS_CHROMEOS_ASH) || BUILDFLAG(IS_CHROMEOS_LACROS)
   // Threading features.
   base::PlatformThread::InitThreadPostFieldTrial();

chrome/browser/about_flags.cc

@@ -222,7 +222,6 @@
 #include "components/content_creation/notes/core/note_features.h"
 #include "components/content_creation/reactions/core/reactions_features.h"
 #include "components/external_intents/android/external_intents_features.h"
-#include "components/power_scheduler/power_scheduler_features.h"
 #include "components/translate/content/android/translate_message.h"
 #include "components/webapps/browser/android/features.h"
 #else  // BUILDFLAG(IS_ANDROID)
@@ -6964,13 +6963,6 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(features::kConsolidatedSiteStorageControls)},
 
 #if BUILDFLAG(IS_ANDROID)
-    {"cpu-affinity-restrict-to-little-cores",
-     flag_descriptions::kCpuAffinityRestrictToLittleCoresName,
-     flag_descriptions::kCpuAffinityRestrictToLittleCoresDescription,
-     kOsAndroid,
-     FEATURE_VALUE_TYPE(
-         power_scheduler::features::kCpuAffinityRestrictToLittleCores)},
-
     {"enable-surface-control", flag_descriptions::kAndroidSurfaceControlName,
      flag_descriptions::kAndroidSurfaceControlDescription, kOsAndroid,
      FEATURE_VALUE_TYPE(features::kAndroidSurfaceControl)},

components/power_scheduler/BUILD.gn

@@ -18,15 +18,6 @@ component("power_scheduler") {
     "traced_power_mode.h",
   ]
 
-  if (is_android) {
-    sources += [
-      "power_scheduler.cc",
-      "power_scheduler.h",
-      "power_scheduler_features.cc",
-      "power_scheduler_features.h",
-    ]
-  }
-
   defines = [ "IS_POWER_SCHEDULER_IMPL" ]
 
   deps = [
@@ -39,29 +30,10 @@ source_set("unit_tests") {
   testonly = true
   sources = [ "power_mode_arbiter_unittest.cc" ]
 
-  if (is_android) {
-    sources += [ "power_scheduler_unittest.cc" ]
-  }
-
   deps = [
     ":power_scheduler",
     "//base/test:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
-
-if (is_android) {
-  java_cpp_features("java_features_srcjar") {
-    # External code should depend on ":power_scheduler_java" instead.
-    visibility = [ ":*" ]
-    sources = [ "power_scheduler_features.cc" ]
-    template = "java/src/org/chromium/components/power_scheduler/PowerSchedulerFeatures.java.tmpl"
-  }
-
-  android_library("power_scheduler_java") {
-    # Right now, this only includes the Java features. But if we need more Java
-    # files, they should be added here as necessary.
-    srcjar_deps = [ ":java_features_srcjar" ]
-  }
-}