--- a/gfx/gl/GLContextProviderCGL.mm
+++ b/gfx/gl/GLContextProviderCGL.mm
@@ -351,30 +351,25 @@ GLContextProviderCGL::CreateOffscreen(co
     return gl.forget();
 }
 
 static RefPtr<GLContext> gGlobalContext;
 
 GLContext*
 GLContextProviderCGL::GetGlobalContext()
 {
-    if (!sCGLLibrary.EnsureInitialized()) {
-        return nullptr;
-    }
+    static bool triedToCreateContext = false;
+    if (!triedToCreateContext) {
+        triedToCreateContext = true;
 
-    if (!gGlobalContext) {
-        // There are bugs in some older drivers with pbuffers less
-        // than 16x16 in size; also 16x16 is POT so that we can do
-        // a FBO with it on older video cards.  A FBO context for
-        // sharing is preferred since it has no associated target.
-        gGlobalContext = CreateOffscreenFBOContext(CreateContextFlags::NONE);
-        if (!gGlobalContext || !static_cast<GLContextCGL*>(gGlobalContext.get())->Init()) {
+        MOZ_RELEASE_ASSERT(!gGlobalContext);
+        gGlobalContext = CreateHeadless(0);
+
+        if (!gGlobalContext) {
             NS_WARNING("Couldn't init gGlobalContext.");
-            gGlobalContext = nullptr;
-            return nullptr;
         }
     }
 
     return gGlobalContext;
 }
 
 void
 GLContextProviderCGL::Shutdown()

--- a/gfx/gl/GLContextProviderEAGL.mm
+++ b/gfx/gl/GLContextProviderEAGL.mm
@@ -238,21 +238,24 @@ GLContextProviderEAGL::CreateOffscreen(c
     return glContext.forget();
 }
 
 static RefPtr<GLContext> gGlobalContext;
 
 GLContext*
 GLContextProviderEAGL::GetGlobalContext()
 {
-    if (!gGlobalContext) {
-        gGlobalContext = CreateEAGLContext(true, nullptr);
-        if (!gGlobalContext ||
-            !static_cast<GLContextEAGL*>(gGlobalContext.get())->Init())
-        {
+    static bool triedToCreateContext = false;
+    if (!triedToCreateContext) {
+        triedToCreateContext = true;
+
+        MOZ_RELEASE_ASSERT(!gGlobalContext);
+        gGlobalContext = CreateHeadless(0);
+
+        if (!gGlobalContext) {
             MOZ_CRASH("Failed to create global context");
         }
     }
 
     return gGlobalContext;
 }
 
 void

--- a/gfx/gl/GLContextProviderGLX.cpp
+++ b/gfx/gl/GLContextProviderGLX.cpp
@@ -1319,32 +1319,25 @@ GLContextProviderGLX::CreateOffscreen(co
 
     return gl.forget();
 }
 
 /*static*/ GLContext*
 GLContextProviderGLX::GetGlobalContext()
 {
     // TODO: get GLX context sharing to work well with multiple threads
-    if (gfxEnv::DisableContextSharingGlx()) {
+    if (gfxEnv::DisableContextSharingGlx())
         return nullptr;
-    }
 
     static bool triedToCreateContext = false;
-    if (!triedToCreateContext && !gGlobalContext) {
+    if (!triedToCreateContext) {
         triedToCreateContext = true;
 
-        IntSize dummySize = IntSize(16, 16);
-        SurfaceCaps dummyCaps = SurfaceCaps::Any();
-        // StaticPtr doesn't support assignments from already_AddRefed,
-        // so use a temporary nsRefPtr to make the reference counting
-        // fall out correctly.
-        RefPtr<GLContext> holder;
-        holder = CreateOffscreenPixmapContext(dummySize, dummyCaps);
-        gGlobalContext = holder;
+        MOZ_RELEASE_ASSERT(!gGlobalContext);
+        gGlobalContext = CreateHeadless(0);
     }
 
     return gGlobalContext;
 }
 
 /*static*/ void
 GLContextProviderGLX::Shutdown()
 {

--- a/gfx/gl/GLContextProviderWGL.cpp
+++ b/gfx/gl/GLContextProviderWGL.cpp
@@ -688,36 +688,22 @@ GLContextProviderWGL::CreateOffscreen(co
     return gl.forget();
 }
 
 static StaticRefPtr<GLContextWGL> gGlobalContext;
 
 /*static*/ GLContext*
 GLContextProviderWGL::GetGlobalContext()
 {
-    if (!sWGLLib.EnsureInitialized()) {
-        return nullptr;
-    }
-
     static bool triedToCreateContext = false;
-
-    if (!triedToCreateContext && !gGlobalContext) {
+    if (!triedToCreateContext) {
         triedToCreateContext = true;
 
-        // conveniently, we already have what we need...
-        SurfaceCaps dummyCaps = SurfaceCaps::Any();
-        gGlobalContext = new GLContextWGL(dummyCaps,
-                                          nullptr, true,
-                                          sWGLLib.GetWindowDC(),
-                                          sWGLLib.GetWindowGLContext());
-        if (!gGlobalContext->Init()) {
-            NS_WARNING("Global context GLContext initialization failed?");
-            gGlobalContext = nullptr;
-            return nullptr;
-        }
+        MOZ_RELEASE_ASSERT(!gGlobalContext);
+        gGlobalContext = CreateHeadless(0);
     }
 
     return static_cast<GLContext*>(gGlobalContext);
 }
 
 /*static*/ void
 GLContextProviderWGL::Shutdown()
 {