Bug 1548253 - Port pref cache variables of nsContentUtils to StaticPrefs - dom.script_loader.bytecode_cache.strategy, r=Ehsan

Differential Revision: https://phabricator.services.mozilla.com/D29525

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

dom/base/nsContentUtils.cpp

@@ -314,7 +314,6 @@ bool nsContentUtils::sInitialized = false;
 bool nsContentUtils::sBypassCSSOMOriginCheck = false;
 #endif
 
-int32_t nsContentUtils::sBytecodeCacheStrategy = 0;
 nsCString* nsContentUtils::sJSBytecodeMimeType = nullptr;
 
 nsContentUtils::UserInteractionObserver*
@@ -609,9 +608,6 @@ nsresult nsContentUtils::Init() {
   sBypassCSSOMOriginCheck = getenv("MOZ_BYPASS_CSSOM_ORIGIN_CHECK");
 #endif
 
-  Preferences::AddIntVarCache(&sBytecodeCacheStrategy,
-                              "dom.script_loader.bytecode_cache.strategy", 0);
-
   nsDependentCString buildID(mozilla::PlatformBuildID());
   sJSBytecodeMimeType =
       new nsCString(NS_LITERAL_CSTRING("javascript/moz-bytecode-") + buildID);

dom/base/nsContentUtils.h

@@ -3188,10 +3188,6 @@ class nsContentUtils {
    */
   static bool GetUserIsInteracting();
 
-  // Check pref "dom.script_loader.bytecode_cache.strategy" to see which
-  // heuristic strategy should be used to trigger the caching of the bytecode.
-  static int32_t BytecodeCacheStrategy() { return sBytecodeCacheStrategy; }
-
   // Alternate data MIME type used by the ScriptLoader to register and read
   // bytecode out of the nsCacheInfoChannel.
   static nsCString& JSBytecodeMimeType() { return *sJSBytecodeMimeType; }
@@ -3403,7 +3399,6 @@ class nsContentUtils {
 #ifndef RELEASE_OR_BETA
   static bool sBypassCSSOMOriginCheck;
 #endif
-  static int32_t sBytecodeCacheStrategy;
 
   class UserInteractionObserver;
   static UserInteractionObserver* sUserInteractionObserver;

dom/script/ScriptLoader.cpp

@@ -2386,7 +2386,7 @@ bool ScriptLoader::ShouldCacheBytecode(ScriptLoadRequest* aRequest) {
 
   // Look at the preference to know which strategy (parameters) should be used
   // when the bytecode cache is enabled.
-  int32_t strategy = nsContentUtils::BytecodeCacheStrategy();
+  int32_t strategy = StaticPrefs::dom_script_loader_bytecode_cache_strategy();
 
   // List of parameters used by the strategies.
   bool hasSourceLengthMin = false;

modules/libpref/init/StaticPrefList.h

@@ -548,6 +548,27 @@ VARCACHE_PREF(
   bool, true
 )
 
+// Ignore the heuristics of the bytecode cache, and always record on the first
+// visit. (used for testing purposes).
+
+// Choose one strategy to use to decide when the bytecode should be encoded and
+// saved. The following strategies are available right now:
+//   * -2 : (reader mode) The bytecode cache would be read, but it would never
+//          be saved.
+//   * -1 : (eager mode) The bytecode would be saved as soon as the script is
+//          seen for the first time, independently of the size or last access
+//          time.
+//   *  0 : (default) The bytecode would be saved in order to minimize the
+//          page-load time.
+//
+// Other values might lead to experimental strategies. For more details, have a
+// look at: ScriptLoader::ShouldCacheBytecode function.
+VARCACHE_PREF(
+  "dom.script_loader.bytecode_cache.strategy",
+   dom_script_loader_bytecode_cache_strategy,
+  int32_t, 0
+)
+
 // IMPORTANT: Keep this in condition in sync with all.js. The value
 // of MOZILLA_OFFICIAL is different between full and artifact builds, so without
 // it being specified there, dump is disabled in artifact builds (see Bug 1490412).

modules/libpref/init/all.js

@@ -232,23 +232,6 @@ pref("dom.inputevent.inputtype.enabled", true);
 // Whether the WebMIDI API is enabled
 pref("dom.webmidi.enabled", false);
 
-// Ignore the heuristics of the bytecode cache, and always record on the first
-// visit. (used for testing purposes).
-
-// Choose one strategy to use to decide when the bytecode should be encoded and
-// saved. The following strategies are available right now:
-//   * -2 : (reader mode) The bytecode cache would be read, but it would never
-//          be saved.
-//   * -1 : (eager mode) The bytecode would be saved as soon as the script is
-//          seen for the first time, independently of the size or last access
-//          time.
-//   *  0 : (default) The bytecode would be saved in order to minimize the
-//          page-load time.
-//
-// Other values might lead to experimental strategies. For more details, have a
-// look at: ScriptLoader::ShouldCacheBytecode function.
-pref("dom.script_loader.bytecode_cache.strategy", 0);
-
 #ifdef JS_BUILD_BINAST
 pref("dom.script_loader.binast_encoding.enabled", false);
 pref("dom.script_loader.binast_encoding.domain.restrict.list", "*.facebook.com,static.xx.fbcdn.net");