Fix 2D canvas drawImage handling of non-invertible transform matrices

Source/core/html/canvas/CanvasRenderingContext2D.cpp

Index: Source/core/html/canvas/CanvasRenderingContext2D.cpp
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.cpp b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
index ad626b2ac61dbe69366729cc585de45edfb25b38..c5bfa6d21158ef005ee5f6c184745209414fa2e4 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.cpp
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
@@ -1282,7 +1282,11 @@ void CanvasRenderingContext2D::drawImageInternal(CanvasImageSource* imageSource,
         SkMatrix ctm = c->getTotalMatrix();
         SkMatrix invCtm;
         if (!ctm.invert(&invCtm)) {
-            ASSERT_NOT_REACHED(); // There is an earlier check for invertibility
+            // There is an earlier check for invertibility, but the arithmetic
+            // in AffineTransform is not exactly identical, so it is possible
+            // for SkMatrix to find the transform to be non-invertible at this stage.
+            // crbug.com/504687
+            return;
         }
         c->save();
         c->concat(invCtm);