[Android WebView] Update viewport size and scale calculation to match WebView Classic

Source/WebKit/chromium/src/WebViewImpl.cpp

Index: Source/WebKit/chromium/src/WebViewImpl.cpp
diff --git a/Source/WebKit/chromium/src/WebViewImpl.cpp b/Source/WebKit/chromium/src/WebViewImpl.cpp
index 4942175219dcbe5170a29553c1926f4b721a4244..69faa7258d517defcfac7892510355be326065b4 100644
--- a/Source/WebKit/chromium/src/WebViewImpl.cpp
+++ b/Source/WebKit/chromium/src/WebViewImpl.cpp
@@ -3043,6 +3043,10 @@ void WebViewImpl::computePageScaleFactorLimits()
             viewWidthNotIncludingScrollbars -= view->verticalScrollbar()->width();
         m_minimumPageScaleFactor = max(m_minimumPageScaleFactor, static_cast<float>(viewWidthNotIncludingScrollbars) / contentsSize().width());
         m_maximumPageScaleFactor = max(m_minimumPageScaleFactor, m_maximumPageScaleFactor);
+        if (m_initialPageScaleFactorOverride != -1) {
+            m_minimumPageScaleFactor = min(m_minimumPageScaleFactor, m_initialPageScaleFactorOverride);
+            m_maximumPageScaleFactor = max(m_maximumPageScaleFactor, m_initialPageScaleFactorOverride);
+        }
     }
     ASSERT(m_minimumPageScaleFactor <= m_maximumPageScaleFactor);