Fix WebGL context restoration logic. The retry mechanism was broken when the ownership of the WebGr…

Source/platform/graphics/gpu/Extensions3DUtil.h

Index: Source/platform/graphics/gpu/Extensions3DUtil.h
diff --git a/Source/platform/graphics/gpu/Extensions3DUtil.h b/Source/platform/graphics/gpu/Extensions3DUtil.h
index 88adc322f0ed786b59d49bc101cc089abe01bbf1..3251192950ef5425fb819327fcfc5d17dd2a7be3 100644
--- a/Source/platform/graphics/gpu/Extensions3DUtil.h
+++ b/Source/platform/graphics/gpu/Extensions3DUtil.h
@@ -20,7 +20,8 @@ namespace WebCore {
 
 class PLATFORM_EXPORT Extensions3DUtil {
 public:
-    Extensions3DUtil(blink::WebGraphicsContext3D*);
+    // Creates a new Extensions3DUtil. If the passed WebGraphicsContext3D has been spontaneously lost, returns null.
+    static PassOwnPtr<Extensions3DUtil> create(blink::WebGraphicsContext3D*);
     ~Extensions3DUtil();
 
     bool supportsExtension(const String& name);
@@ -30,7 +31,8 @@ public:
     static bool canUseCopyTextureCHROMIUM(GLenum destFormat, GLenum destType, GLint level);
 
 private:
-    void initializeExtensions();
+    Extensions3DUtil(blink::WebGraphicsContext3D*);
+    bool initializeExtensions();
 
     blink::WebGraphicsContext3D* m_context;
     HashSet<String> m_enabledExtensions;