Refactor viewport initialization logic out of WebViewImpl.

Source/core/testing/Internals.cpp

Index: Source/core/testing/Internals.cpp
diff --git a/Source/core/testing/Internals.cpp b/Source/core/testing/Internals.cpp
index 1042d3522647a53f607d2e7d96d40253c34b592f..f57023a4a9ee5478e5d5c2ec3c59d8d07478cf71 100644
--- a/Source/core/testing/Internals.cpp
+++ b/Source/core/testing/Internals.cpp
@@ -906,6 +906,35 @@ void Internals::setPagination(Document* document, const String& mode, int gap, i
     page->setPagination(pagination);
 }
 
+static FloatSize convertToUserSpace(const FloatSize& deviceSize, float devicePixelRatio)

[abarth-chromium, 2013/05/20 18:22:25]

What is "user space" ?

+{
+    FloatSize result = deviceSize;
+    if (devicePixelRatio != 1)
+        result.scale(1 / devicePixelRatio);
+    return result;
+}
+
+static ViewportAttributes computeViewportAttributes(ViewportArguments args, int desktopWidth, int deviceWidth, int deviceHeight, float devicePixelRatio, IntSize visibleViewport)
+{
+    FloatSize initialViewportSize = convertToUserSpace(visibleViewport, devicePixelRatio);
+    FloatSize deviceSize = convertToUserSpace(FloatSize(deviceWidth, deviceHeight), devicePixelRatio);
+
+    return args.resolve(initialViewportSize, deviceSize, desktopWidth);
+}
+
+static float computeMinimumScaleFactorForContentContained(const ViewportAttributes& result, const IntSize& visibleViewport, const IntSize& contentsSize)
+{
+    FloatSize viewportSize(visibleViewport);
+    return max<float>(result.minimumScale, max(viewportSize.width() / contentsSize.width(), viewportSize.height() / contentsSize.height()));
+}
+
+static void restrictMinimumScaleFactorToViewportSize(ViewportAttributes& result, IntSize visibleViewport, float devicePixelRatio)
+{
+    FloatSize viewportSize = convertToUserSpace(visibleViewport, devicePixelRatio);
+
+    result.minimumScale = max<float>(result.minimumScale, max(viewportSize.width() / result.layoutSize.width(), viewportSize.height() / result.layoutSize.height()));
+}

[abarth-chromium, 2013/05/20 18:22:25]

I don't understand why we need all of this code in Internals.  Maybe we should
output information in a different format that requires less computation?

+
 String Internals::configurationForViewport(Document* document, float devicePixelRatio, int deviceWidth, int deviceHeight, int availableWidth, int availableHeight, ExceptionCode& ec)
 {
     if (!document || !document->page()) {
@@ -919,9 +948,8 @@ String Internals::configurationForViewport(Document* document, float devicePixel
     ViewportArguments arguments = page->viewportArguments();
     ViewportAttributes attributes = computeViewportAttributes(arguments, defaultLayoutWidthForNonMobilePages, deviceWidth, deviceHeight, devicePixelRatio, IntSize(availableWidth, availableHeight));
     restrictMinimumScaleFactorToViewportSize(attributes, IntSize(availableWidth, availableHeight), devicePixelRatio);
-    restrictScaleFactorToInitialScaleIfNotUserScalable(attributes);
 
-    return "viewport size " + String::number(attributes.layoutSize.width()) + "x" + String::number(attributes.layoutSize.height()) + " scale " + String::number(attributes.initialScale) + " with limits [" + String::number(attributes.minimumScale) + ", " + String::number(attributes.maximumScale) + "] and userScalable " + (attributes.userScalable ? "true" : "false");
+    return "viewport size " + String::number(attributes.layoutSize.width()) + "x" + String::number(attributes.layoutSize.height()) + " scale " + String::number(attributes.initialScale) + " with limits [" + String::number(attributes.minimumScale) + ", " + String::number(attributes.maximumScale) + "] and userScalable " + (arguments.userZoom ? "true" : "false");
 }
 
 bool Internals::wasLastChangeUserEdit(Element* textField, ExceptionCode& ec)