[M102 merge] mac: adds experiment to use 60hz on 120hz devices

This will be used to collect data to understand the cost of this. This includes an about:flag option to disable it. BUG=1323358 (cherry picked from commit 8073e2d) Change-Id: Ib6c86ccaa561ebf854a076adf795df860c4b6519 Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3632908 Reviewed-by: ccameron chromium <ccameron@chromium.org> Commit-Queue: Scott Violet <sky@chromium.org> Cr-Original-Commit-Position: refs/heads/main@{#1001199} Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3647318 Auto-Submit: Scott Violet <sky@chromium.org> Commit-Queue: ccameron chromium <ccameron@chromium.org> Cr-Commit-Position: refs/branch-heads/5005@{#736} Cr-Branched-From: 5b4d945-refs/heads/main@{#992738}
chromium · May 13, 2022 · 478a76a · 478a76a
1 parent 4f7c728
commit 478a76a
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Showing 8 changed files with 40 additions and 5 deletions.
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
@@ -4284,7 +4284,6 @@ const FeatureEntry kFeatureEntries[] = {
      kOsLinux | kOsLacros | kOsMac,
      FEATURE_VALUE_TYPE(
          password_manager::features::kSkipUndecryptablePasswords)},
-
 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_MAC)
 
 #if BUILDFLAG(ENABLE_VR)
@@ -8524,6 +8523,12 @@ const FeatureEntry kFeatureEntries[] = {
      FEATURE_VALUE_TYPE(
          autofill::features::kAutofillEnableVirtualCardFidoEnrollment)},
 
+#if BUILDFLAG(IS_MAC)
+    {"force-60hz", flag_descriptions::kForce60HzName,
+     flag_descriptions::kForce60HzDescription, kOsMac,
+     FEATURE_VALUE_TYPE(display::features::kForce60Hz)},
+#endif  // BUILDFLAG(IS_MAC)
+
     // NOTE: Adding a new flag requires adding a corresponding entry to enum
     // "LoginCustomFlags" in tools/metrics/histograms/enums.xml. See "Flag
     // Histograms" in tools/metrics/histograms/README.md (run the

diff --git a/chrome/browser/flag-metadata.json b/chrome/browser/flag-metadata.json
@@ -3287,6 +3287,11 @@
     "owners": [ "cmp", "pwnall" ],
     "expiry_milestone": 102
   },
+  {
+    "name": "force-60hz",
+    "owners": [ "sky" ],
+    "expiry_milestone": 106
+  },
   {
     "name": "force-color-profile",
     "owners": [ "ccameron" ],

diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
@@ -5706,6 +5706,12 @@ const char kSkipUndecryptablePasswordsDescription[] =
     "there are undecryptable ones.";
 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_MAC)
 
+#if BUILDFLAG(IS_MAC)
+const char kForce60HzName[] = "Use 60hz instead of 120hz";
+const char kForce60HzDescription[] =
+    "If enabled, on devices with a refresh rate of 120hz, 60hz is used.";
+#endif  // BUILDFLAG(IS_MAC)
+
 // Feature flags --------------------------------------------------------------
 
 #if BUILDFLAG(CHROME_WIDE_ECHO_CANCELLATION)

diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
@@ -3288,6 +3288,11 @@ extern const char kSkipUndecryptablePasswordsName[];
 extern const char kSkipUndecryptablePasswordsDescription[];
 #endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_MAC)
 
+#if BUILDFLAG(IS_MAC)
+extern const char kForce60HzName[];
+extern const char kForce60HzDescription[];
+#endif  // BUILDFLAG(IS_MAC)
+
 // Feature flags --------------------------------------------------------------
 
 #if BUILDFLAG(CHROME_WIDE_ECHO_CANCELLATION)

diff --git a/tools/metrics/histograms/enums.xml b/tools/metrics/histograms/enums.xml
@@ -55359,6 +55359,7 @@ from previous Chrome versions.
   <int value="7444737" label="NTPSuggestionsStandaloneUI:disabled"/>
   <int value="7533886" label="disable-offer-store-unmasked-wallet-cards"/>
   <int value="7642326" label="hdrnet-override"/>
+  <int value="7804608" label="Force60Hz:enabled"/>
   <int value="8891567" label="CaptionSettings:enabled"/>
   <int value="9609535" label="BrowsingDataLifetimeManager:disabled"/>
   <int value="10405060" label="BluetoothSessionizedMetrics:disabled"/>
@@ -57713,6 +57714,7 @@ from previous Chrome versions.
       label="AutofillAlwaysReturnCloudTokenizedCard:enabled"/>
   <int value="1634897915" label="password-import-export:enabled"/>
   <int value="1634980726" label="VrShellExperimentalRendering:disabled"/>
+  <int value="1635519293" label="Force60Hz:disabled"/>
   <int value="1635695770" label="CSSContainerQueries:disabled"/>
   <int value="1635755615" label="ScanAppMultiPageScan:disabled"/>
   <int value="1635986352" label="ContextMenuSearchWithGoogleLens:enabled"/>

diff --git a/ui/display/display_features.cc b/ui/display/display_features.cc
@@ -43,5 +43,9 @@ bool IsHardwareMirrorModeEnabled() {
   return base::FeatureList::IsEnabled(kEnableHardwareMirrorMode);
 }
 
+#if BUILDFLAG(IS_MAC)
+const base::Feature kForce60Hz{"Force60Hz", base::FEATURE_DISABLED_BY_DEFAULT};
+#endif
+
 }  // namespace features
 }  // namespace display
diff --git a/ui/display/display_features.h b/ui/display/display_features.h
@@ -24,6 +24,11 @@ DISPLAY_EXPORT extern const base::Feature kEnableHardwareMirrorMode;
 
 DISPLAY_EXPORT bool IsHardwareMirrorModeEnabled();
 
+#if BUILDFLAG(IS_MAC)
+// If enabled, vsync of 120 is forced to 60.
+DISPLAY_EXPORT extern const base::Feature kForce60Hz;
+#endif
+
 }  // namespace features
 }  // namespace display
 

diff --git a/ui/display/mac/display_link_mac.cc b/ui/display/mac/display_link_mac.cc
@@ -15,6 +15,7 @@
 #include "base/task/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/trace_event/trace_event.h"
+#include "ui/display/display_features.h"
 
 namespace base {
 
@@ -163,8 +164,7 @@ DisplayLinkMac::DisplayLinkMac(
     base::ScopedTypeRef<CVDisplayLinkRef> display_link)
     : display_id_(display_id),
       display_link_(display_link),
-      force_60hz_(
-          base::CommandLine::ForCurrentProcess()->HasSwitch("force-60hz")) {
+      force_60hz_(base::FeatureList::IsEnabled(display::features::kForce60Hz)) {
   DisplayLinkMap& all_display_links = GetAllDisplayLinks();
   DCHECK(all_display_links.find(display_id) == all_display_links.end());
   if (all_display_links.empty()) {
@@ -236,8 +236,11 @@ void DisplayLinkMac::UpdateVSyncParameters(const CVTimeStamp& cv_time) {
 
   timebase_ = base::TimeTicks::FromMachAbsoluteTime(cv_time.hostTime);
   interval_ = base::Microseconds(int64_t{interval_us.ValueOrDie()});
-  if (force_60hz_)
-    interval_ = std::max(base::Hertz(60), interval_);
+  // Use a range as interval is not always exactly 120.
+  if (force_60hz_ && interval_ <= base::Hertz(115) &&
+      interval_ >= base::Hertz(125)) {
+    interval_ *= 2;
+  }
   timebase_and_interval_valid_ = true;
 
   // Don't restart the display link for 10 seconds.