[2.38] Destroy acc surface and egl target in nonCompositedWebGL mode

In case of nonCompositedWebGL enabled (Lightning) egl target from
renderer backend was never destroyed that was causing crash
on egl backend destruction as the backend outlived the target.

This change ensures that egl target is destroyed
on LayerTreeHost and ThreadedCompositor destruction
freeing native window.

Also need to ensure that static window context from
NicosiaGCGLLayer is destroyed before egl target destruction
(otherwise it will crash). Add ref counting and destroy
global window context when no longer needed.
(Can be recreated if neccesary)

Author: asurdej-comcast

Source/WebCore/platform/graphics/nicosia/texmap/NicosiaGCGLLayer.cpp

@@ -44,11 +44,7 @@ namespace Nicosia {
 using namespace WebCore;
 
 static std::unique_ptr<GLContext> s_windowContext;
-
-static void terminateWindowContext()
-{
-    s_windowContext = nullptr;
-}
+static int s_windowContextRefCount = 0;
 
 std::unique_ptr<GCGLLayer> GCGLLayer::create(WebCore::GraphicsContextGLOpenGL& context)
 {
@@ -60,7 +56,6 @@ std::unique_ptr<GCGLLayer> GCGLLayer::create(WebCore::GraphicsContextGLOpenGL& c
     } else {
         if (!s_windowContext) {
             s_windowContext = GLContext::createContextForWindow(reinterpret_cast<GLNativeWindowType>(attributes.nativeWindowID), &PlatformDisplay::sharedDisplayForCompositing());
-            std::atexit(terminateWindowContext);
         }
         if (s_windowContext)
             return makeUnique<GCGLLayer>(context);
@@ -80,11 +75,21 @@ GCGLLayer::GCGLLayer(GraphicsContextGLOpenGL& context)
     : m_context(context)
     , m_contentLayer(Nicosia::ContentLayer::create(Nicosia::ContentLayerTextureMapperImpl::createFactory(*this)))
 {
+    ASSERT(s_windowContext);
+    s_windowContextRefCount++;
 }
 
 GCGLLayer::~GCGLLayer()
 {
     downcast<ContentLayerTextureMapperImpl>(m_contentLayer->impl()).invalidateClient();
+
+    if (m_context.contextAttributes().renderTarget != GraphicsContextGLRenderTarget::Offscreen) {
+        ASSERT(s_windowContext);
+        s_windowContextRefCount--;
+        if (!s_windowContextRefCount) {
+            s_windowContext = nullptr;
+        }
+    }
 }
 
 bool GCGLLayer::makeContextCurrent()

Source/WebKit/Shared/CoordinatedGraphics/threadedcompositor/ThreadedCompositor.cpp

@@ -110,15 +110,17 @@ void ThreadedCompositor::invalidate()
     m_compositingRunLoop->stopUpdates();
     m_displayRefreshMonitor->invalidate();
     m_compositingRunLoop->performTaskSync([this, protectedThis = Ref { *this }] {
-        if (!m_context || !m_context->makeContextCurrent())
-            return;
+        if (m_context) {
+            if (!m_context->makeContextCurrent())
+                return;
 
-        // Update the scene at this point ensures the layers state are correctly propagated
-        // in the ThreadedCompositor and in the CompositingCoordinator.
-        updateSceneWithoutRendering();
+            // Update the scene at this point ensures the layers state are correctly propagated
+            // in the ThreadedCompositor and in the CompositingCoordinator.
+            updateSceneWithoutRendering();
 
-        m_scene->purgeGLResources();
-        m_context = nullptr;
+            m_scene->purgeGLResources();
+            m_context = nullptr;
+        }
         m_client.didDestroyGLContext();
         m_scene = nullptr;
     });