--- a/dom/media/platforms/wmf/WMFVideoMFTManager.cpp
+++ b/dom/media/platforms/wmf/WMFVideoMFTManager.cpp
@@ -419,39 +419,41 @@ public:
     , mBackend(LayersBackend::LAYERS_D3D11)
     , mKnowsCompositor(aKnowsCompositor)
     , mFailureReason(aFailureReason)
   {
   }
 
   NS_IMETHOD Run() override {
     NS_ASSERTION(NS_IsMainThread(), "Must be on main thread.");
+    const bool deblacklistingForTelemetry =
+      XRE_IsGPUProcess() && gfxPrefs::PDMWMFDeblacklistingForTelemetryInGPUProcess();
     nsACString* failureReason = &mFailureReason;
     nsCString secondFailureReason;
     if (mBackend == LayersBackend::LAYERS_D3D11 &&
       gfxPrefs::PDMWMFAllowD3D11() && IsWin8OrLater()) {
       const nsCString& blacklistedDLL = FindD3D11BlacklistedDLL();
-      if (!blacklistedDLL.IsEmpty()) {
+      if (!deblacklistingForTelemetry && !blacklistedDLL.IsEmpty()) {
         failureReason->AppendPrintf("D3D11 blacklisted with DLL %s",
                                     blacklistedDLL.get());
       } else {
         mDXVA2Manager =
           DXVA2Manager::CreateD3D11DXVA(mKnowsCompositor, *failureReason);
         if (mDXVA2Manager) {
           return NS_OK;
         }
       }
       // Try again with d3d9, but record the failure reason
       // into a new var to avoid overwriting the d3d11 failure.
       failureReason = &secondFailureReason;
       mFailureReason.Append(NS_LITERAL_CSTRING("; "));
     }
 
     const nsCString& blacklistedDLL = FindD3D9BlacklistedDLL();
-    if (!blacklistedDLL.IsEmpty()) {
+    if (!deblacklistingForTelemetry && !blacklistedDLL.IsEmpty()) {
       mFailureReason.AppendPrintf("D3D9 blacklisted with DLL %s",
                                   blacklistedDLL.get());
     } else {
       mDXVA2Manager =
         DXVA2Manager::CreateD3D9DXVA(mKnowsCompositor, *failureReason);
       // Make sure we include the messages from both attempts (if applicable).
       mFailureReason.Append(secondFailureReason);
     }

--- a/gfx/thebes/gfxPrefs.h
+++ b/gfx/thebes/gfxPrefs.h
@@ -662,16 +662,17 @@ private:
                                                                HardwareVideoDecodingForceEnabled, bool, false);
 #ifdef XP_WIN
   DECL_GFX_PREF(Live, "media.windows-media-foundation.allow-d3d11-dxva", PDMWMFAllowD3D11, bool, true);
   DECL_GFX_PREF(Live, "media.windows-media-foundation.max-dxva-videos", PDMWMFMaxDXVAVideos, uint32_t, 8);
   DECL_GFX_PREF(Live, "media.windows-media-foundation.use-nv12-format", PDMWMFUseNV12Format, bool, true);
   DECL_GFX_PREF(Once, "media.windows-media-foundation.use-sync-texture", PDMWMFUseSyncTexture, bool, true);
   DECL_GFX_PREF(Live, "media.wmf.low-latency.enabled", PDMWMFLowLatencyEnabled, bool, false);
   DECL_GFX_PREF(Live, "media.wmf.skip-blacklist", PDMWMFSkipBlacklist, bool, false);
+  DECL_GFX_PREF(Live, "media.wmf.deblacklisting-for-telemetry-in-gpu-process", PDMWMFDeblacklistingForTelemetryInGPUProcess, bool, false);
 #endif
 
   // These affect how line scrolls from wheel events will be accelerated.
   DECL_GFX_PREF(Live, "mousewheel.acceleration.factor",        MouseWheelAccelerationFactor, int32_t, -1);
   DECL_GFX_PREF(Live, "mousewheel.acceleration.start",         MouseWheelAccelerationStart, int32_t, -1);
 
   // This affects whether events will be routed through APZ or not.
   DECL_GFX_PREF(Live, "mousewheel.system_scroll_override_on_root_content.enabled",

--- a/modules/libpref/init/all.js
+++ b/modules/libpref/init/all.js
@@ -368,16 +368,17 @@ pref("media.wmf.enabled", true);
 pref("media.wmf.decoder.thread-count", -1);
 pref("media.wmf.low-latency.enabled", false);
 pref("media.wmf.skip-blacklist", false);
 pref("media.wmf.vp9.enabled", true);
 pref("media.wmf.allow-unsupported-resolutions", false);
 pref("media.windows-media-foundation.allow-d3d11-dxva", true);
 pref("media.wmf.disable-d3d11-for-dlls", "igd11dxva64.dll: 20.19.15.4463, 20.19.15.4454, 20.19.15.4444, 20.19.15.4416, 20.19.15.4404, 20.19.15.4390, 20.19.15.4380, 20.19.15.4377, 20.19.15.4364, 20.19.15.4360, 20.19.15.4352, 20.19.15.4331, 20.19.15.4326, 20.19.15.4300; igd10iumd32.dll: 20.19.15.4444, 20.19.15.4424, 20.19.15.4409, 20.19.15.4390, 20.19.15.4380, 20.19.15.4360, 10.18.10.4358, 20.19.15.4331, 20.19.15.4312, 20.19.15.4300, 10.18.15.4281, 10.18.15.4279, 10.18.10.4276, 10.18.15.4268, 10.18.15.4256, 10.18.10.4252, 10.18.15.4248, 10.18.14.4112, 10.18.10.3958, 10.18.10.3496, 10.18.10.3431, 10.18.10.3412, 10.18.10.3355, 9.18.10.3234, 9.18.10.3071, 9.18.10.3055, 9.18.10.3006; igd10umd32.dll: 9.17.10.4229, 9.17.10.3040, 9.17.10.2857, 8.15.10.2274, 8.15.10.2272, 8.15.10.2246, 8.15.10.1840, 8.15.10.1808; igd10umd64.dll: 9.17.10.4229, 9.17.10.2857, 10.18.10.3496; isonyvideoprocessor.dll: 4.1.2247.8090, 4.1.2153.6200; tosqep.dll: 1.2.15.526, 1.1.12.201, 1.0.11.318, 1.0.11.215, 1.0.10.1224; tosqep64.dll: 1.1.12.201, 1.0.11.215; nvwgf2um.dll: 22.21.13.8253, 22.21.13.8233, 22.21.13.8205, 22.21.13.8189, 22.21.13.8178, 22.21.13.8165, 21.21.13.7892, 21.21.13.7878, 21.21.13.7866, 21.21.13.7849, 21.21.13.7654, 21.21.13.7653, 21.21.13.7633, 21.21.13.7619, 21.21.13.7563, 21.21.13.7306, 21.21.13.7290, 21.21.13.7270, 21.21.13.7254, 21.21.13.6939, 21.21.13.6926, 21.21.13.6909, 21.21.13.4201, 21.21.13.4200, 10.18.13.6881, 10.18.13.6839, 10.18.13.6510, 10.18.13.6472, 10.18.13.6143, 10.18.13.5946, 10.18.13.5923, 10.18.13.5921, 10.18.13.5891, 10.18.13.5887, 10.18.13.5582, 10.18.13.5445, 10.18.13.5382, 10.18.13.5362, 9.18.13.4788, 9.18.13.4752, 9.18.13.4725, 9.18.13.4709, 9.18.13.4195, 9.18.13.4192, 9.18.13.4144, 9.18.13.4052, 9.18.13.3788, 9.18.13.3523, 9.18.13.3235, 9.18.13.3165, 9.18.13.2723, 9.18.13.2702, 9.18.13.1422, 9.18.13.1407, 9.18.13.1106, 9.18.13.546; atidxx32.dll: 21.19.151.3, 21.19.142.257, 21.19.137.514, 21.19.137.1, 21.19.134.1, 21.19.128.7, 21.19.128.4, 20.19.0.32837, 20.19.0.32832, 8.17.10.682, 8.17.10.671, 8.17.10.661, 8.17.10.648, 8.17.10.644, 8.17.10.625, 8.17.10.605, 8.17.10.581, 8.17.10.569, 8.17.10.560, 8.17.10.545, 8.17.10.539, 8.17.10.531, 8.17.10.525, 8.17.10.520, 8.17.10.519, 8.17.10.514, 8.17.10.511, 8.17.10.494, 8.17.10.489, 8.17.10.483, 8.17.10.453, 8.17.10.451, 8.17.10.441, 8.17.10.436, 8.17.10.432, 8.17.10.425, 8.17.10.418, 8.17.10.414, 8.17.10.401, 8.17.10.395, 8.17.10.385, 8.17.10.378, 8.17.10.362, 8.17.10.355, 8.17.10.342, 8.17.10.331, 8.17.10.318, 8.17.10.310, 8.17.10.286, 8.17.10.269, 8.17.10.261, 8.17.10.247, 8.17.10.240, 8.15.10.212; atidxx64.dll: 21.19.151.3, 21.19.142.257, 21.19.137.514, 21.19.137.1, 21.19.134.1, 21.19.128.7, 21.19.128.4, 20.19.0.32832, 8.17.10.682, 8.17.10.661, 8.17.10.644, 8.17.10.625; nvumdshim.dll: 10.18.13.6822");
 pref("media.wmf.disable-d3d9-for-dlls", "igdumd64.dll: 8.15.10.2189, 8.15.10.2119, 8.15.10.2104, 8.15.10.2102, 8.771.1.0; atiumd64.dll: 7.14.10.833, 7.14.10.867, 7.14.10.885, 7.14.10.903, 7.14.10.911, 8.14.10.768, 9.14.10.1001, 9.14.10.1017, 9.14.10.1080, 9.14.10.1128, 9.14.10.1162, 9.14.10.1171, 9.14.10.1183, 9.14.10.1197, 9.14.10.945, 9.14.10.972, 9.14.10.984, 9.14.10.996");
+pref("media.wmf.deblacklisting-for-telemetry-in-gpu-process", true);
 #endif
 #if defined(MOZ_FFMPEG)
 #if defined(XP_MACOSX)
 pref("media.ffmpeg.enabled", false);
 #else
 pref("media.ffmpeg.enabled", true);
 #endif
 pref("media.libavcodec.allow-obsolete", false);