Bug 1575806 - Cleanup a bit preference-stylesheet-related code. r=heycam

Some of it was dead code, another was inlining a not very useful function (and
in one case redundant, since EnsureInitialized() happened right after
Refresh()).

Differential Revision: https://phabricator.services.mozilla.com/D43042

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

layout/base/nsPresContext.cpp

@@ -331,15 +331,6 @@ bool nsPresContext::IsChrome() const {
   return Document()->IsInChromeDocShell();
 }
 
-bool nsPresContext::IsChromeOriginImage() const {
-  return Document()->IsBeingUsedAsImage() &&
-         Document()->IsDocumentURISchemeChrome();
-}
-
-void nsPresContext::GetDocumentColorPreferences() {
-  PreferenceSheet::EnsureInitialized();
-}
-
 void nsPresContext::GetUserPreferences() {
   if (!GetPresShell()) {
     // No presshell means nothing to do here.  We'll do this when we
@@ -350,8 +341,7 @@ void nsPresContext::GetUserPreferences() {
   mAutoQualityMinFontSizePixelsPref =
       Preferences::GetInt("browser.display.auto_quality_min_font_size");
 
-  // * document colors
-  GetDocumentColorPreferences();
+  PreferenceSheet::EnsureInitialized();
 
   mSendAfterPaintToContent = Preferences::GetBool(
       "dom.send_after_paint_to_content", mSendAfterPaintToContent);
@@ -1336,12 +1326,10 @@ void nsPresContext::SysColorChangedInternal() {
   // Invalidate cached '-moz-windows-accent-color-applies' media query:
   RefreshSystemMetrics();
 
+  // Reset default background and foreground colors for the document since they
+  // may be using system colors
   PreferenceSheet::Refresh();
 
-  // Reset default background and foreground colors for the document since
-  // they may be using system colors
-  GetDocumentColorPreferences();
-
   // The system color values are computed to colors in the style data,
   // so normal style data comparison is sufficient here.
   RebuildAllStyleData(nsChangeHint(0), RestyleHint{0});

layout/base/nsPresContext.h

@@ -806,7 +806,6 @@ class nsPresContext : public nsISupports,
 
   // Is this presentation in a chrome docshell?
   bool IsChrome() const;
-  bool IsChromeOriginImage() const;
 
   // Public API for native theme code to get style internals.
   bool HasAuthorSpecifiedRules(const nsIFrame* aFrame,
@@ -1041,7 +1040,6 @@ class nsPresContext : public nsISupports,
   void SetImgAnimations(nsIContent* aParent, uint16_t aMode);
   void SetSMILAnimations(mozilla::dom::Document* aDoc, uint16_t aNewMode,
                          uint16_t aOldMode);
-  void GetDocumentColorPreferences();
 
   void PreferenceChanged(const char* aPrefName);