Fix viewer last image and zoomer.

Change-Id: If4f614510b3d2a5802e87350b8f09797d9c52c96
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/332036
Commit-Queue: Greg Daniel <egdaniel@google.com>
Auto-Submit: Greg Daniel <egdaniel@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index 7334bf1..5253c90 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -2451,13 +2451,13 @@
                             SkGetPackedB32(pixel), SkGetPackedA32(pixel));
             }
 
-            fImGuiLayer.skiaWidget(avail, [=](SkCanvas* c) {
+            fImGuiLayer.skiaWidget(avail, [=, lastImage = fLastImage](SkCanvas* c) {
                 // Translate so the region of the image that's under the mouse cursor is centered
                 // in the zoom canvas:
                 c->scale(zoomFactor, zoomFactor);
                 c->translate(avail.x * 0.5f / zoomFactor - x - 0.5f,
                              avail.y * 0.5f / zoomFactor - y - 0.5f);
-                c->drawImage(this->fLastImage, 0, 0);
+                c->drawImage(lastImage, 0, 0);
 
                 SkPaint outline;
                 outline.setStyle(SkPaint::kStroke_Style);