Bug 1570082 - Convert content.sink.enable_perf_mode to static pref r=njn

Converts content.sink.enable_perf_mode to a static pref. Also removes nsContentSink::InitializeStatics(), since this is the last varcache pref in the function.

Differential Revision: https://phabricator.services.mozilla.com/D40141

--HG--
extra : moz-landing-system : lando

dom/base/nsContentSink.cpp

@@ -134,12 +134,6 @@ nsContentSink::~nsContentSink() {
     mDocument->RemoveObserver(this);
   }
 }
-int32_t nsContentSink::sEnablePerfMode;
-
-void nsContentSink::InitializeStatics() {
-  Preferences::AddIntVarCache(&sEnablePerfMode, "content.sink.enable_perf_mode",
-                              0);
-}
 
 nsresult nsContentSink::Init(Document* aDoc, nsIURI* aURI,
                              nsISupports* aContainer, nsIChannel* aChannel) {
@@ -173,8 +167,8 @@ nsresult nsContentSink::Init(Document* aDoc, nsIURI* aURI,
 
   mBackoffCount = StaticPrefs::content_notify_backoffcount();
 
-  if (sEnablePerfMode != 0) {
+  if (StaticPrefs::content_sink_enable_perf_mode() != 0) {
-    mDynamicLowerValue = sEnablePerfMode == 1;
+    mDynamicLowerValue = StaticPrefs::content_sink_enable_perf_mode() == 1;
     FavorPerformanceHint(!mDynamicLowerValue, 0);
   }
 
@@ -1483,7 +1477,7 @@ nsresult nsContentSink::WillParseImpl(void) {
 
   uint32_t currentTime = PR_IntervalToMicroseconds(PR_IntervalNow());
 
-  if (sEnablePerfMode == 0) {
+  if (StaticPrefs::content_sink_enable_perf_mode() == 0) {
     nsViewManager* vm = presShell->GetViewManager();
     NS_ENSURE_TRUE(vm, NS_ERROR_FAILURE);
     uint32_t lastEventTime;

dom/base/nsContentSink.h

@@ -118,8 +118,6 @@ class nsContentSink : public nsICSSLoaderObserver,
   bool LinkContextIsOurDocument(const nsAString& aAnchor);
   bool Decode5987Format(nsAString& aEncoded);
 
-  static void InitializeStatics();
-
  protected:
   nsContentSink();
   virtual ~nsContentSink();
@@ -338,9 +336,6 @@ class nsContentSink : public nsICSSLoaderObserver,
 
   nsRevocableEventPtr<nsRunnableMethod<nsContentSink, void, false> >
       mProcessLinkHeaderEvent;
-
-  // Should we switch between perf-mode and interactive-mode
-  static int32_t sEnablePerfMode;
 };
 
 #endif  // _nsContentSink_h_

layout/build/nsLayoutStatics.cpp

@@ -245,7 +245,6 @@ nsresult nsLayoutStatics::Initialize() {
   MediaManager::StartupInit();
   CubebUtils::InitLibrary();
 
-  nsContentSink::InitializeStatics();
   nsHtml5Module::InitializeStatics();
   mozilla::dom::FallbackEncoding::Initialize();
   nsLayoutUtils::Initialize();

modules/libpref/init/StaticPrefList.yaml

@@ -1058,6 +1058,15 @@
   value: 2000000
   mirror: always
 
+# Should we switch between perf-mode and interactive-mode?
+# 0 = Switch
+# 1 = Interactive mode
+# 2 = Perf mode
+- name: content.sink.enable_perf_mode
+  type: int32_t
+  value: 0
+  mirror: always
+
 #---------------------------------------------------------------------------
 # Prefs starting with "device."
 #---------------------------------------------------------------------------