Get skiaserve working on Windows.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1903203003

Review URL: https://codereview.chromium.org/1903203003
diff --git a/tools/skiaserve/Request.cpp b/tools/skiaserve/Request.cpp
index 7cbc9ef..b16c5cf 100644
--- a/tools/skiaserve/Request.cpp
+++ b/tools/skiaserve/Request.cpp
@@ -98,7 +98,8 @@
     // Playback into picture recorder
     SkIRect bounds = this->getBounds();
     SkPictureRecorder recorder;
-    SkCanvas* canvas = recorder.beginRecording(bounds.width(), bounds.height());
+    SkCanvas* canvas = recorder.beginRecording(SkIntToScalar(bounds.width()),
+                                               SkIntToScalar(bounds.height()));
 
     fDebugCanvas->draw(canvas);