Bug 1802625 - Allow strokes to be cached as textures even when GPU stroking is off. r=jrmuizel

This fixes an incidental bug with the pref to turn off GPU stroking. It's not supposed to disable
caching strokes as textures. This allows that to work again even if prefed off.

Differential Revision: https://phabricator.services.mozilla.com/D163307

dom/canvas/DrawTargetWebgl.cpp

@@ -2536,9 +2536,7 @@ void PathCache::ClearVertexRanges() {
 
 inline bool DrawTargetWebgl::ShouldAccelPath(
     const DrawOptions& aOptions, const StrokeOptions* aStrokeOptions) {
-  return mWebglValid && SupportsDrawOptions(aOptions) &&
-         (!aStrokeOptions || mSharedContext->mPathAccelStroke) &&
-         PrepareContext();
+  return mWebglValid && SupportsDrawOptions(aOptions) && PrepareContext();
 }
 
 bool DrawTargetWebgl::SharedContext::DrawPathAccel(
@@ -2634,7 +2632,7 @@ bool DrawTargetWebgl::SharedContext::DrawPathAccel(
   }
 
   if (mPathVertexCapacity > 0 && !handle && entry && !aShadow &&
-      SupportsPattern(aPattern) &&
+      SupportsPattern(aPattern) && (!aStrokeOptions || mPathAccelStroke) &&
       entry->GetPath().mPath.num_types <= mPathMaxComplexity) {
     if (entry->GetVertexRange().IsValid()) {
       // If there is a valid cached vertex data in the path vertex buffer, then