[Android WebView] Treat zero values in viewport arguments specially

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 0aff89cd3852d81b7ee3cc3806ee06ecfc121a19..00cc71b08f06f7ed36fe49589fcddb5229840434 100644
--- a/Source/web/tests/WebFrameTest.cpp
+++ b/Source/web/tests/WebFrameTest.cpp
@@ -713,6 +713,34 @@ TEST_F(WebFrameTest, WideViewportInitialScaleDoesNotExpandFixedLayoutWidth)
     EXPECT_EQ(viewportWidth, webViewImpl->mainFrameImpl()->frameView()->fixedLayoutSize().width());
 }
 
+TEST_F(WebFrameTest, ZeroValuesQuirk)
+{
+    registerMockedHttpURLLoad("viewport-zero-values.html");
+
+    FixedLayoutTestWebViewClient client;
+    client.m_screenInfo.deviceScaleFactor = 1;
+    int viewportWidth = 640;
+    int viewportHeight = 480;
+
+    m_webView = FrameTestHelpers::createWebView(true, 0, &client);
+    m_webView->enableFixedLayoutMode(true);
+    m_webView->settings()->setViewportEnabled(true);
+    m_webView->settings()->setSupportDeprecatedTargetDensityDPI(true);
+    m_webView->settings()->setViewportMetaZeroValuesQuirk(true);
+    FrameTestHelpers::loadFrame(m_webView->mainFrame(), m_baseURL + "viewport-zero-values.html");
+    Platform::current()->unitTestSupport()->serveAsynchronousMockedRequests();
+    m_webView->resize(WebSize(viewportWidth, viewportHeight));
+
+    WebViewImpl* webViewImpl = static_cast<WebViewImpl*>(m_webView);
+    EXPECT_EQ(viewportWidth, webViewImpl->mainFrameImpl()->frameView()->fixedLayoutSize().width());
+    EXPECT_EQ(1.0f, m_webView->pageScaleFactor());
+
+    m_webView->settings()->setUseWideViewport(true);
+    m_webView->layout();
+    EXPECT_EQ(viewportWidth, webViewImpl->mainFrameImpl()->frameView()->fixedLayoutSize().width());
+    EXPECT_EQ(1.0f, m_webView->pageScaleFactor());
+}
+
 TEST_F(WebFrameTest, ScaleFactorShouldNotOscillate)
 {
     registerMockedHttpURLLoad("scale_oscillate.html");