Bug 733562 - Offscreen FBO must not be created for Global Shared context. r=bjacob

gfx/gl/GLContext.h

@@ -571,6 +571,11 @@ public:
 #endif
     }
 
+    enum ContextFlags {
+        ContextFlagsNone = 0x0,
+        ContextFlagsGlobal = 0x1
+    };
+
     enum GLContextType {
         ContextTypeUnknown,
         ContextTypeWGL,

gfx/gl/GLContextProviderCGL.mm

@@ -590,7 +590,8 @@ CreateOffscreenFBOContext(const ContextFormat& aFormat,
 
 already_AddRefed<GLContext>
 GLContextProviderCGL::CreateOffscreen(const gfxIntSize& aSize,
-                                      const ContextFormat& aFormat)
+                                      const ContextFormat& aFormat,
+                                      const ContextFlags flags)
 {
     ContextFormat actualFormat(aFormat);
 

gfx/gl/GLContextProviderEGL.cpp

@@ -1897,7 +1897,8 @@ GLContextEGL::CreateEGLPixmapOffscreenContext(const gfxIntSize& aSize,
 // often without the ability to texture from them directly.
 already_AddRefed<GLContext>
 GLContextProviderEGL::CreateOffscreen(const gfxIntSize& aSize,
-                                      const ContextFormat& aFormat)
+                                      const ContextFormat& aFormat,
+                                      const ContextFlags aFlags)
 {
     if (!sEGLLibrary.EnsureInitialized()) {
         return nsnull;
@@ -1917,7 +1918,7 @@ GLContextProviderEGL::CreateOffscreen(const gfxIntSize& aSize,
         return nsnull;
 
     gfxIntSize fboSize = usePBuffers ? glContext->OffscreenActualSize() : aSize;
-    if (!glContext->ResizeOffscreenFBO(fboSize, !usePBuffers))
+    if (!(aFlags & GLContext::ContextFlagsGlobal) && !glContext->ResizeOffscreenFBO(fboSize, !usePBuffers))
         return nsnull;
 
     return glContext.forget();
@@ -1928,7 +1929,7 @@ GLContextProviderEGL::CreateOffscreen(const gfxIntSize& aSize,
     if (!glContext)
         return nsnull;
 
-    if (!glContext->ResizeOffscreenFBO(glContext->OffscreenActualSize(), true))
+    if (!(aFlags & GLContext::ContextFlagsGlobal) && !glContext->ResizeOffscreenFBO(glContext->OffscreenActualSize(), true))
         return nsnull;
 
     return glContext.forget();
@@ -1940,7 +1941,7 @@ GLContextProviderEGL::CreateOffscreen(const gfxIntSize& aSize,
         return nsnull;
     }
 
-    if (!gUseBackingSurface && !glContext->ResizeOffscreenFBO(glContext->OffscreenActualSize(), true)) {
+    if (!(aFlags & GLContext::ContextFlagsGlobal) && !gUseBackingSurface && !glContext->ResizeOffscreenFBO(glContext->OffscreenActualSize(), true)) {
         // we weren't able to create the initial
         // offscreen FBO, so this is dead
         return nsnull;
@@ -1999,7 +2000,8 @@ GLContextProviderEGL::GetGlobalContext()
         // CreateOffscreen can call us re-entrantly.
         nsRefPtr<GLContext> ctx =
             GLContextProviderEGL::CreateOffscreen(gfxIntSize(16, 16),
-                                                  ContextFormat(ContextFormat::BasicRGB24));
+                                                  ContextFormat(ContextFormat::BasicRGB24),
+                                                  GLContext::ContextFlagsGlobal);
         gGlobalContext = ctx;
         if (gGlobalContext)
             gGlobalContext->SetIsGlobalSharedContext(true);

gfx/gl/GLContextProviderGLX.cpp

@@ -1292,7 +1292,8 @@ DONE_CREATING_PIXMAP:
 
 already_AddRefed<GLContext>
 GLContextProviderGLX::CreateOffscreen(const gfxIntSize& aSize,
-                                      const ContextFormat& aFormat)
+                                      const ContextFormat& aFormat,
+                                      const ContextFlags)
 {
     nsRefPtr<GLContextGLX> glContext =
         CreateOffscreenPixmapContext(aSize, aFormat, true);

gfx/gl/GLContextProviderImpl.h

@@ -45,6 +45,7 @@
 class THEBES_API GL_CONTEXT_PROVIDER_NAME
 {
 public:
+    typedef GLContext::ContextFlags ContextFlags;
     /**
      * Create a context that renders to the surface of the widget that is
      * passed in.  The context is always created with an RGB pixel format,
@@ -90,7 +91,8 @@ public:
      */
     static already_AddRefed<GLContext>
     CreateOffscreen(const gfxIntSize& aSize,
-                    const ContextFormat& aFormat = ContextFormat::BasicRGBA32Format);
+                    const ContextFormat& aFormat = ContextFormat::BasicRGBA32Format,
+                    const ContextFlags aFlags = GLContext::ContextFlagsNone);
 
     /**
      * Try to create a GL context from native surface for arbitrary gfxASurface

gfx/gl/GLContextProviderNull.cpp

@@ -46,7 +46,8 @@ GLContextProviderNull::CreateForWindow(nsIWidget*)
 
 already_AddRefed<GLContext>
 GLContextProviderNull::CreateOffscreen(const gfxIntSize&,
-                                       const ContextFormat&)
+                                       const ContextFormat&,
+                                       const ContextFlags)
 {
     return nsnull;
 }

gfx/gl/GLContextProviderOSMesa.cpp

@@ -259,7 +259,8 @@ GLContextProviderOSMesa::CreateForWindow(nsIWidget *aWidget)
 
 already_AddRefed<GLContext>
 GLContextProviderOSMesa::CreateOffscreen(const gfxIntSize& aSize,
-                                         const ContextFormat& aFormat)
+                                         const ContextFormat& aFormat,
+                                         const ContextFlags)
 {
     if (!sOSMesaLibrary.EnsureInitialized()) {
         return nsnull;

gfx/gl/GLContextProviderWGL.cpp

@@ -751,7 +751,8 @@ CreateWindowOffscreenContext(const ContextFormat& aFormat)
 
 already_AddRefed<GLContext>
 GLContextProviderWGL::CreateOffscreen(const gfxIntSize& aSize,
-                                      const ContextFormat& aFormat)
+                                      const ContextFormat& aFormat,
+                                      const ContextFlags)
 {
     if (!sWGLLibrary.EnsureInitialized()) {
         return nsnull;