foo.diff

diff --git a/src/protocol/graphics.ts b/src/protocol/graphics.ts
index de57eb74..a7fbbdc4 100644
--- a/src/protocol/graphics.ts
+++ b/src/protocol/graphics.ts
@@ -115,8 +115,10 @@ function onMouseEvents(events: MouseEvent[], store: UIStore) {
   store.dispatch(actions.setEventsForType(gMouseClickEvents, "mousedown"));
 }
 
+let onCanvasUpdate = details => {};
+
 export function setupGraphics(store: UIStore) {
-  gStore = store;
+  onCanvasUpdate = details => store.dispatch(actions.setCanvas(details));
 
   ThreadFront.sessionWaiter.promise.then((sessionId: string) => {
     client.Graphics.findPaints({}, sessionId);
@@ -355,16 +357,14 @@ export function refreshGraphics() {
     }
   }
 
-  gStore.dispatch(
-    actions.setCanvas({
-      scale,
-      gDevicePixelRatio,
-      width: image.width,
-      height: image.height,
-      left: offsetLeft,
-      top: offsetTop,
-    })
-  );
+  onCanvasUpdate({
+    scale,
+    gDevicePixelRatio,
+    width: image.width,
+    height: image.height,
+    left: offsetLeft,
+    top: offsetTop,
+  });
 
   // Apply the same transforms to any displayed highlighter.
   const highlighterContainer = document.querySelector(".highlighter-container") as HTMLElement;