Zoom instead of autosizing for desktop sites.

Source/web/tests/WebFrameTest.cpp

Index: Source/web/tests/WebFrameTest.cpp
diff --git a/Source/web/tests/WebFrameTest.cpp b/Source/web/tests/WebFrameTest.cpp
index 93b7ceb6b03faf8c753103139523fc77a0b7c03b..6e0028582097158658b7751e6639ddfedf863aa4 100644
--- a/Source/web/tests/WebFrameTest.cpp
+++ b/Source/web/tests/WebFrameTest.cpp
@@ -2088,6 +2088,28 @@ TEST_F(WebFrameTest, CanOverrideScaleLimits)
     EXPECT_EQ(2.0f, webViewHelper.webView()->maximumPageScaleFactor());
 }
 
+TEST_F(WebFrameTest, DeviceScaleAdjustmentReducesLayoutWidth)
+{
+    UseMockScrollbarSettings mockScrollbarSettings;
+
+    registerMockedHttpURLLoad("hello_world.html");
+
+    int viewportWidth = 1280;
+    int viewportHeight = 800;
+    float deviceScaleAdjustment = 1.3f;
+
+    FrameTestHelpers::WebViewHelper webViewHelper;
+    webViewHelper.initializeAndLoad(m_baseURL + "hello_world.html", true);
+    webViewHelper.webView()->settings()->setViewportEnabled(true);
+    webViewHelper.webView()->settings()->setDeviceScaleAdjustment(deviceScaleAdjustment);
+
+    webViewHelper.webView()->resize(WebSize(viewportWidth, viewportHeight));
+    webViewHelper.webView()->layout();
+
+    EXPECT_EQ(static_cast<int>(viewportWidth / deviceScaleAdjustment),
+        webViewHelper.webViewImpl()->page()->mainFrame()->view()->layoutSize().width());
+}
+
 TEST_F(WebFrameTest, updateOverlayScrollbarLayers)
 {
     UseMockScrollbarSettings mockScrollbarSettings;