Bug 1550422 - P19. Convert gfxPrefs::LayersWindowRecordingPath to gfxVars. r=jrmuizel

StaticPrefs doesn't support nsCString type and the changes required to support this would be rather big. Seeing that there was only a single gfxPrefs using this, and this is a "Once" pref ; we move it to gfxVars instead.

Differential Revision: https://phabricator.services.mozilla.com/D31462

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

gfx/config/gfxVars.h

@@ -49,7 +49,8 @@ class gfxVarReceiver;
   _(ProfDirectory, nsString, nsString())                           \
   _(UseOMTP, bool, false)                                          \
   _(AllowD3D11KeyedMutex, bool, false)                             \
-  _(SystemTextQuality, int32_t, 5 /* CLEARTYPE_QUALITY */)
+  _(SystemTextQuality, int32_t, 5 /* CLEARTYPE_QUALITY */)         \
+  _(LayersWindowRecordingPath, nsCString, nsCString())
 
 /* Add new entries above this line. */
 

gfx/layers/CompositionRecorder.cpp

@@ -7,7 +7,7 @@
 #include "CompositionRecorder.h"
 #include "gfxUtils.h"
 #include "mozilla/gfx/2D.h"
-#include "gfxPrefs.h"
+#include "mozilla/gfx/gfxVars.h"
 
 #include <ctime>
 #include <iomanip>
@@ -37,7 +37,7 @@ void CompositionRecorder::WriteCollectedFrames() {
   std::time_t t = std::time(nullptr);
   std::tm tm = *std::localtime(&t);
   std::stringstream str;
-  str << gfxPrefs::LayersWindowRecordingPath() << "windowrecording-"
+  str << gfxVars::LayersWindowRecordingPath() << "windowrecording-"
       << std::put_time(&tm, "%Y%m%d%H%M%S");
 
 #ifdef XP_WIN

gfx/thebes/gfxPlatform.cpp

@@ -893,6 +893,10 @@ void gfxPlatform::Init() {
     }
 
     gfxUtils::RemoveShaderCacheFromDiskIfNecessary();
+
+    nsAutoCString path;
+    Preferences::GetCString("layers.windowrecording.path", path);
+    gfxVars::SetLayersWindowRecordingPath(path);
   }
 
   // Drop a note in the crash report if we end up forcing an option that could

gfx/thebes/gfxPrefs.h

@@ -289,8 +289,6 @@ class gfxPrefs final {
   // will keep these in an alphabetical order to make it easier to see if a
   // method accessing a pref already exists. Just add yours in the list.
 
-  DECL_GFX_PREF(Once, "layers.windowrecording.path",           LayersWindowRecordingPath, std::string, std::string());
-
   // WARNING:
   // Please make sure that you've added your new preference to the list above
   // in alphabetical order.