Fix DM race in SVGSrc

dm/DMSrcSink.cpp

Index: dm/DMSrcSink.cpp
diff --git a/dm/DMSrcSink.cpp b/dm/DMSrcSink.cpp
index dd54f00e2bd1a8d68996177103644b2e79c55334..17714fb04642ec874705ec68ae25c12f115f19fa 100644
--- a/dm/DMSrcSink.cpp
+++ b/dm/DMSrcSink.cpp
@@ -1098,46 +1098,43 @@ static const SkSize kDefaultSVGSize = SkSize::Make(1000, 1000);
 // Used to force-scale tiny fixed-size images.
 static const SkSize kMinimumSVGSize = SkSize::Make(128, 128);
 
-SVGSrc::SVGSrc(Path path) : fPath(path), fScale(1) {}
-
-Error SVGSrc::ensureDom() const {
-    if (!fDom) {
-        SkFILEStream stream(fPath.c_str());
-        if (!stream.isValid()) {
-            return SkStringPrintf("Unable to open file: %s", fPath.c_str());
-        }
-        fDom = SkSVGDOM::MakeFromStream(stream);
-        if (!fDom) {
-            return SkStringPrintf("Unable to parse file: %s", fPath.c_str());
-        }
-
-        const SkSize& sz = fDom->containerSize();
-        if (sz.isEmpty()) {
-            // no intrinsic size
-            fDom->setContainerSize(kDefaultSVGSize);
-        } else {
-            fScale = SkTMax(1.f, SkTMax(kMinimumSVGSize.width()  / sz.width(),
-                                        kMinimumSVGSize.height() / sz.height()));
-        }
-    }
-
-    return "";
+SVGSrc::SVGSrc(Path path)
+    : fName(SkOSPath::Basename(path.c_str()))
+    , fScale(1) {
+
+  SkFILEStream stream(path.c_str());
+  if (!stream.isValid()) {
+      return;
+  }
+  fDom = SkSVGDOM::MakeFromStream(stream);
+  if (!fDom) {
+      return;
+  }
+
+  const SkSize& sz = fDom->containerSize();
+  if (sz.isEmpty()) {
+      // no intrinsic size
+      fDom->setContainerSize(kDefaultSVGSize);
+  } else {
+      fScale = SkTMax(1.f, SkTMax(kMinimumSVGSize.width()  / sz.width(),
+                                  kMinimumSVGSize.height() / sz.height()));
+  }
 }
 
 Error SVGSrc::draw(SkCanvas* canvas) const {
-    Error err = this->ensureDom();
-    if (err.isEmpty()) {
-        SkAutoCanvasRestore acr(canvas, true);
-        canvas->scale(fScale, fScale);
-        fDom->render(canvas);
+    if (!fDom) {
+        return SkStringPrintf("Unable to parse file: %s", fName.c_str());
     }
 
-    return err;
+    SkAutoCanvasRestore acr(canvas, true);
+    canvas->scale(fScale, fScale);
+    fDom->render(canvas);
+
+    return "";
 }
 
 SkISize SVGSrc::size() const {
-    Error err = this->ensureDom();
-    if (!err.isEmpty()) {
+    if (!fDom) {
         return SkISize::Make(0, 0);
     }
 
@@ -1145,7 +1142,7 @@ SkISize SVGSrc::size() const {
                         fDom->containerSize().height() * fScale).toRound();
 }
 
-Name SVGSrc::name() const { return SkOSPath::Basename(fPath.c_str()); }
+Name SVGSrc::name() const { return fName; }
 
 bool SVGSrc::veto(SinkFlags flags) const {
     // No need to test to non-(raster||gpu) or indirect backends.