CanvasRenderingContext2D should update the render tree to avoid stale computed style.

Source/core/html/canvas/CanvasRenderingContext2D.cpp

Index: Source/core/html/canvas/CanvasRenderingContext2D.cpp
diff --git a/Source/core/html/canvas/CanvasRenderingContext2D.cpp b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
index 8825d1842718098d9dd353f2a3a8cc1a7ae9b5e0..c576916701b9bb45c9905610f317115943237bb9 100644
--- a/Source/core/html/canvas/CanvasRenderingContext2D.cpp
+++ b/Source/core/html/canvas/CanvasRenderingContext2D.cpp
@@ -1950,6 +1950,7 @@ void CanvasRenderingContext2D::setFont(const String& newFont)
     // Map the <canvas> font into the text style. If the font uses keywords like larger/smaller, these will work
     // relative to the canvas.
     RefPtr<RenderStyle> newStyle = RenderStyle::create();
+    canvas()->document().updateRenderTreeIfNeeded();
     if (RenderStyle* computedStyle = canvas()->computedStyle()) {
         FontDescription elementFontDescription(computedStyle->fontDescription());
         // Reset the computed size to avoid inheriting the zoom factor from the <canvas> element.