Fix 2D canvas state persistency after OffscreenCanvas.transferToImageBitmap

third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp

Index: third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp
diff --git a/third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp b/third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp
index d54204ea18c56d148fc3e8ff9213d10177bc65ec..9668f847da74eb4312a6191c9b6f9d46dbe66e5a 100644
--- a/third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp
+++ b/third_party/WebKit/Source/modules/canvas2d/BaseRenderingContext2D.cpp
@@ -93,6 +93,21 @@ void BaseRenderingContext2D::restore()
     validateStateStack();
 }
 
+void BaseRenderingContext2D::restoreMatrixClipStack(SkCanvas* c) const
+{
+    if (!c)
+        return;
+    HeapVector<Member<CanvasRenderingContext2DState>>::const_iterator currState;
+    DCHECK(m_stateStack.begin() < m_stateStack.end());
+    for (currState = m_stateStack.begin(); currState < m_stateStack.end(); currState++) {
+        c->setMatrix(SkMatrix::I());
+        currState->get()->playbackClips(c);
+        c->setMatrix(affineTransformToSkMatrix(currState->get()->transform()));
+        c->save();
+    }
+    c->restore();
+}
+
 static inline void convertCanvasStyleToUnionType(CanvasStyle* style, StringOrCanvasGradientOrCanvasPattern& returnValue)
 {
     if (CanvasGradient* gradient = style->getCanvasGradient()) {