From b9ef728a9dacf88adae213632a0077fc88738c42 Mon Sep 17 00:00:00 2001
From: Andrew Osmond <aosmond@mozilla.com>
Date: Wed, 30 Sep 2020 20:05:28 +0000
Subject: [PATCH] Bug 1668360 - Invert WebRender feature config to be enabled
 by default. r=jrmuizel

This has no functional change beyond our telemetry reporting. It inverts
our feature configuration such that we get an explicit reason why we
don't turn on some features, instead of just "disabled by default."

Differential Revision: https://phabricator.services.mozilla.com/D91980
---
 gfx/config/gfxConfigManager.cpp | 88 +++++++++++++++++++--------------
 1 file changed, 51 insertions(+), 37 deletions(-)

diff --git a/gfx/config/gfxConfigManager.cpp b/gfx/config/gfxConfigManager.cpp
index 8c9169886bc9..44a245fe526c 100644
--- a/gfx/config/gfxConfigManager.cpp
+++ b/gfx/config/gfxConfigManager.cpp
@@ -223,36 +223,35 @@ void gfxConfigManager::ConfigureWebRender() {
 
   bool guardedByQualifiedPref = ConfigureWebRenderQualified();
 
-  mFeatureWr->DisableByDefault(FeatureStatus::OptIn,
-                               "WebRender is an opt-in feature",
-                               "FEATURE_FAILURE_DEFAULT_OFF"_ns);
+  mFeatureWr->EnableByDefault();
 
   // envvar works everywhere; note that we need this for testing in CI.
   // Prior to bug 1523788, the `prefEnabled` check was only done on Nightly,
   // so as to prevent random users from easily enabling WebRender on
   // unqualified hardware in beta/release.
   if (mWrEnvForceEnabled) {
-    mFeatureWr->UserEnable("Force enabled by envvar");
+    mFeatureWr->UserForceEnable("Force enabled by envvar");
   } else if (mWrForceEnabled) {
-    mFeatureWr->UserEnable("Force enabled by pref");
-  } else if (mFeatureWrQualified->IsEnabled()) {
+    mFeatureWr->UserForceEnable("Force enabled by pref");
+  } else if (mWrForceDisabled ||
+             (mWrEnvForceDisabled && mWrQualifiedOverride.isNothing())) {
+    // If the user set the pref to force-disable, let's do that. This
+    // will override all the other enabling prefs
+    // (gfx.webrender.enabled, gfx.webrender.all, and
+    // gfx.webrender.all.qualified).
+    mFeatureWr->UserDisable("User force-disabled WR",
+                            "FEATURE_FAILURE_USER_FORCE_DISABLED"_ns);
+  }
+
+  if (!mFeatureWrQualified->IsEnabled()) {
+    mFeatureWr->Disable(FeatureStatus::Disabled, "Not qualified",
+                        "FEATURE_FAILURE_NOT_QUALIFIED"_ns);
+  } else if (guardedByQualifiedPref && !mWrQualified) {
     // If the HW is qualified, we enable if either the HW has been qualified
     // on the release channel (i.e. it's no longer guarded by the qualified
     // pref), or if the qualified pref is enabled.
-    if (!guardedByQualifiedPref) {
-      mFeatureWr->UserEnable("Qualified in release");
-    } else if (mWrQualified) {
-      mFeatureWr->UserEnable("Qualified enabled by pref");
-    }
-  }
-
-  // If the user set the pref to force-disable, let's do that. This will
-  // override all the other enabling prefs (gfx.webrender.enabled,
-  // gfx.webrender.all, and gfx.webrender.all.qualified).
-  if (mWrForceDisabled ||
-      (mWrEnvForceDisabled && mWrQualifiedOverride.isNothing())) {
-    mFeatureWr->UserDisable("User force-disabled WR",
-                            "FEATURE_FAILURE_USER_FORCE_DISABLED"_ns);
+    mFeatureWr->Disable(FeatureStatus::Disabled, "Control group for experiment",
+                        "FEATURE_FAILURE_IN_EXPERIMENT"_ns);
   }
 
   // HW_COMPOSITING being disabled implies interfacing with the GPU might break
@@ -276,24 +275,39 @@ void gfxConfigManager::ConfigureWebRender() {
                              "FEATURE_FAILURE_XRENDER"_ns);
   }
 
-  mFeatureWrAngle->DisableByDefault(FeatureStatus::OptIn,
-                                    "WebRender ANGLE is an opt-in feature",
-                                    "FEATURE_FAILURE_DEFAULT_OFF"_ns);
-
-  if (mFeatureD3D11HwAngle && mWrForceAngle) {
-    if (!mFeatureD3D11HwAngle->IsEnabled()) {
-      mFeatureWr->ForceDisable(FeatureStatus::UnavailableNoAngle,
-                               "ANGLE is disabled",
-                               mFeatureD3D11HwAngle->GetFailureId());
-    } else if (!mFeatureGPUProcess->IsEnabled() &&
-               (!mIsNightly || !mWrForceAngleNoGPUProcess)) {
-      // WebRender with ANGLE relies on the GPU process when on Windows
-      mFeatureWr->ForceDisable(FeatureStatus::UnavailableNoGpuProcess,
-                               "GPU Process is disabled",
-                               "FEATURE_FAILURE_GPU_PROCESS_DISABLED"_ns);
-    } else if (mFeatureWr->IsEnabled()) {
-      mFeatureWrAngle->UserEnable("Enabled");
+  mFeatureWrAngle->EnableByDefault();
+  if (mFeatureD3D11HwAngle) {
+    if (mWrForceAngle) {
+      if (!mFeatureD3D11HwAngle->IsEnabled()) {
+        mFeatureWrAngle->ForceDisable(FeatureStatus::UnavailableNoAngle,
+                                      "ANGLE is disabled",
+                                      mFeatureD3D11HwAngle->GetFailureId());
+      } else if (!mFeatureGPUProcess->IsEnabled() &&
+                 (!mIsNightly || !mWrForceAngleNoGPUProcess)) {
+        // WebRender with ANGLE relies on the GPU process when on Windows
+        mFeatureWrAngle->ForceDisable(
+            FeatureStatus::UnavailableNoGpuProcess, "GPU Process is disabled",
+            "FEATURE_FAILURE_GPU_PROCESS_DISABLED"_ns);
+      } else if (!mFeatureWr->IsEnabled()) {
+        mFeatureWrAngle->ForceDisable(FeatureStatus::Unavailable,
+                                      "WebRender disabled",
+                                      "FEATURE_FAILURE_WR_DISABLED"_ns);
+      }
+    } else {
+      mFeatureWrAngle->Disable(FeatureStatus::Disabled, "ANGLE is not forced",
+                               "FEATURE_FAILURE_ANGLE_NOT_FORCED"_ns);
     }
+  } else {
+    mFeatureWrAngle->Disable(FeatureStatus::Unavailable, "OS not supported",
+                             "FEATURE_FAILURE_OS_NOT_SUPPORTED"_ns);
+  }
+
+  if (mWrForceAngle && mFeatureWr->IsEnabled() &&
+      !mFeatureWrAngle->IsEnabled()) {
+    // Ensure we disable WebRender if ANGLE is unavailable and it is required.
+    mFeatureWr->ForceDisable(FeatureStatus::UnavailableNoAngle,
+                             "ANGLE is disabled",
+                             mFeatureWrAngle->GetFailureId());
   }
 
   if (!mFeatureWr->IsEnabled() && mDisableHwCompositingNoWr) {