From 6f21141c391cb0266f63474f7e120d0730d05d18 Mon Sep 17 00:00:00 2001
From: alwu <alwu@mozilla.com>
Date: Tue, 16 Feb 2021 23:53:45 +0000
Subject: [PATCH] Bug 1690372 - part2 : add Telemetry probe for WMF usage.
 r=bryce

Depends on D103836

Differential Revision: https://phabricator.services.mozilla.com/D103837
---
 dom/media/platforms/wmf/WMFDecoderModule.cpp | 12 ++++++++++++
 dom/media/platforms/wmf/WMFDecoderModule.h   |  2 ++
 toolkit/components/telemetry/Scalars.yaml    | 17 +++++++++++++++++
 3 files changed, 31 insertions(+)

diff --git a/dom/media/platforms/wmf/WMFDecoderModule.cpp b/dom/media/platforms/wmf/WMFDecoderModule.cpp
index e1591bf8210f..0475e084018b 100644
--- a/dom/media/platforms/wmf/WMFDecoderModule.cpp
+++ b/dom/media/platforms/wmf/WMFDecoderModule.cpp
@@ -178,6 +178,8 @@ nsresult WMFDecoderModule::Startup() {
 
 already_AddRefed<MediaDataDecoder> WMFDecoderModule::CreateVideoDecoder(
     const CreateDecoderParams& aParams) {
+  ReportUsageForTelemetry();
+
   // In GPU process, only support decoding if an accelerated compositor is
   // known.
   if (XRE_IsGPUProcess() &&
@@ -214,6 +216,8 @@ already_AddRefed<MediaDataDecoder> WMFDecoderModule::CreateVideoDecoder(
 
 already_AddRefed<MediaDataDecoder> WMFDecoderModule::CreateAudioDecoder(
     const CreateDecoderParams& aParams) {
+  ReportUsageForTelemetry();
+
   if (XRE_IsGPUProcess()) {
     // Only allow video in the GPU process.
     return nullptr;
@@ -288,6 +292,8 @@ bool WMFDecoderModule::SupportsMimeType(
 
 bool WMFDecoderModule::Supports(const SupportDecoderParams& aParams,
                                 DecoderDoctorDiagnostics* aDiagnostics) const {
+  ReportUsageForTelemetry();
+
   // In GPU process, only support decoding if video. This only gives a hint of
   // what the GPU decoder *may* support. The actual check will occur in
   // CreateVideoDecoder.
@@ -341,6 +347,12 @@ bool WMFDecoderModule::Supports(const SupportDecoderParams& aParams,
   return false;
 }
 
+void WMFDecoderModule::ReportUsageForTelemetry() const {
+  if (XRE_IsParentProcess() || XRE_IsContentProcess()) {
+    Telemetry::ScalarSet(Telemetry::ScalarID::MEDIA_WMF_PROCESS_USAGE, true);
+  }
+}
+
 }  // namespace mozilla
 
 #undef WFM_DECODER_MODULE_STATUS_MARKER
diff --git a/dom/media/platforms/wmf/WMFDecoderModule.h b/dom/media/platforms/wmf/WMFDecoderModule.h
index 5bd461b1c340..d78ba0363ff0 100644
--- a/dom/media/platforms/wmf/WMFDecoderModule.h
+++ b/dom/media/platforms/wmf/WMFDecoderModule.h
@@ -50,6 +50,8 @@ class WMFDecoderModule : public PlatformDecoderModule {
   WMFDecoderModule() = default;
   virtual ~WMFDecoderModule();
 
+  void ReportUsageForTelemetry() const;
+
   bool mWMFInitialized = false;
 };
 
diff --git a/toolkit/components/telemetry/Scalars.yaml b/toolkit/components/telemetry/Scalars.yaml
index dfa7d29238fd..bf6f1ba7d35e 100644
--- a/toolkit/components/telemetry/Scalars.yaml
+++ b/toolkit/components/telemetry/Scalars.yaml
@@ -2242,6 +2242,23 @@ media:
     record_in_processes:
       - 'content'
 
+  wmf_process_usage:
+    bug_numbers:
+      - 1690372
+    description: >
+      Record whether the WMF decoder module is used in content or chrome process.
+    expires: "93"
+    kind: boolean
+    notification_emails:
+      - alwu@mozilla.com
+      - bvandyk@mozilla.com
+    release_channel_collection: opt-out
+    products:
+      - 'firefox'
+    record_in_processes:
+      - 'main'
+      - 'content'
+
 # The following section contains content process base counters.
 dom.contentprocess:
   buildID_mismatch: