Fix crash in fast/canvas/canvas-empty-image-pattern.html
diff --git a/WebCore/platform/graphics/android/PatternAndroid.cpp b/WebCore/platform/graphics/android/PatternAndroid.cpp
index ff2b522..a787113 100644
--- a/WebCore/platform/graphics/android/PatternAndroid.cpp
+++ b/WebCore/platform/graphics/android/PatternAndroid.cpp
@@ -43,6 +43,8 @@
 SkShader* Pattern::createPlatformPattern(const TransformationMatrix& ) const
 {
     SkBitmapRef* ref = tileImage()->nativeImageForCurrentFrame();
+    if (!ref)
+        return 0;
     SkShader* s = SkShader::CreateBitmapShader(ref->bitmap(),
                                                toTileMode(m_repeatX),
                                                toTileMode(m_repeatY));