Path.transform doesn't work (#3164)

We need to release the typed array so that we can allocate the result value.

Fixes https://github.com/flutter/flutter/issues/6456

DEPS

@@ -57,7 +57,7 @@ deps = {
    Var('fuchsia_git') + '/ftl' + '@' + '5e9935c7205c119ce05098dc1d9c8eaac0595ba4',
 
   'src/lib/tonic':
-   Var('fuchsia_git') + '/tonic' + '@' + 'ba6d0c08d694ba0c4cdc400b763be21f9bd1d8d2',
+   Var('fuchsia_git') + '/tonic' + '@' + 'e1d221b924cb2a604363a8a9dd393d319becc0e8',
 
   'src/lib/zip':
    Var('fuchsia_git') + '/zip' + '@' + '92dc87ca645fe8e9f5151ef6dac86d8311a7222f',

lib/ui/painting/path.cc

@@ -193,9 +193,10 @@ ftl::RefPtr<CanvasPath> CanvasPath::shift(double dx, double dy) {
 }
 
 ftl::RefPtr<CanvasPath> CanvasPath::transform(
-    const tonic::Float64List& matrix4) {
+    tonic::Float64List& matrix4) {
   ftl::RefPtr<CanvasPath> path = CanvasPath::Create();
   path_.transform(ToSkMatrix(matrix4), &path->path_);
+  matrix4.Release();
   return path;
 }
 

lib/ui/painting/path.h

@@ -69,7 +69,7 @@ class CanvasPath : public ftl::RefCountedThreadSafe<CanvasPath>,
   void reset();
   bool contains(double x, double y);
   ftl::RefPtr<CanvasPath> shift(double dx, double dy);
-  ftl::RefPtr<CanvasPath> transform(const tonic::Float64List& matrix4);
+  ftl::RefPtr<CanvasPath> transform(tonic::Float64List& matrix4);
 
   const SkPath& path() const { return path_; }