Improve mobile device rotation behavior.

Source/WebKit/chromium/tests/WebFrameTest.cpp

Index: Source/WebKit/chromium/tests/WebFrameTest.cpp
diff --git a/Source/WebKit/chromium/tests/WebFrameTest.cpp b/Source/WebKit/chromium/tests/WebFrameTest.cpp
index 005801ca99d5768ffe6f9709c407d6dd7f9b1f0b..0dae849169034f1573e05b5e412098a576f5d92e 100644
--- a/Source/WebKit/chromium/tests/WebFrameTest.cpp
+++ b/Source/WebKit/chromium/tests/WebFrameTest.cpp
@@ -37,6 +37,7 @@
 #include "Frame.h"
 #include "FrameTestHelpers.h"
 #include "FrameView.h"
+#include "HitTestResult.h"
 #include "PlatformContextSkia.h"
 #include "Range.h"
 #include "RenderView.h"
@@ -573,6 +574,52 @@ TEST_F(WebFrameTest, pageScaleFactorDoesNotApplyCssTransform)
     EXPECT_EQ(980, webViewImpl->page()->mainFrame()->contentRenderer()->unscaledDocumentRect().width());
     EXPECT_EQ(980, webViewImpl->mainFrameImpl()->frameView()->contentsSize().width());
 }
+
+static WebCore::FloatSize computeRelativeOffset(const WebCore::IntPoint& absoluteOffset, const WebCore::LayoutRect& rect)
+{
+    WebCore::FloatSize relativeOffset = WebCore::FloatPoint(absoluteOffset) - rect.location();
+    relativeOffset.scale(1.f / rect.width(), 1.f / rect.height());

[aelias_OOO_until_Jul13, 2013/04/08 04:24:52]

Delete .f

[jdduke (slow), 2013/04/10 16:58:19]

Done.

+    return relativeOffset;
+}
+
+TEST_F(WebFrameTest, resizePreservesRelativeScrollOffset)
+{
+    registerMockedHttpURLLoad("resize_scroll_anchor.html");
+
+    const WebSize viewportSize = WebSize(320, 240);
+
+    m_webView = FrameTestHelpers::createWebViewAndLoad(m_baseURL + "resize_scroll_anchor.html", true);
+    m_webView->settings()->setViewportEnabled(true);
+    m_webView->setPageScaleFactor(2.0f, WebPoint());
+    m_webView->enableFixedLayoutMode(false);

[aelias_OOO_until_Jul13, 2013/04/08 04:24:52]

This is odd, on Android fixedLayoutMode setting is always true.  This should be
true.  If it breaks your test, something is wrong with the test :).

[jdduke (slow), 2013/04/10 16:58:19]

Nothing broken, I was too lazy to check the default setting.

+    WebViewImpl* webViewImpl = static_cast<WebViewImpl*>(m_webView);
+
+    // Resize at origin
+    webViewImpl->resize(WebSize(viewportSize.width, viewportSize.height));
+    webViewImpl->mainFrame()->setScrollOffset(WebSize());
+    ASSERT_EQ(WebSize(), webViewImpl->mainFrame()->scrollOffset());

[aelias_OOO_until_Jul13, 2013/04/08 04:24:52]

Delete this assert.

[jdduke (slow), 2013/04/10 16:58:19]

Done.

+    webViewImpl->resize(WebSize(viewportSize.height * 2 , viewportSize.width / 2));
+    EXPECT_EQ(WebSize(), webViewImpl->mainFrame()->scrollOffset());
+
+    // Resize as rotation
+    const WebSize scrollOffset = WebSize(200, 400);
+    webViewImpl->resize(WebSize(viewportSize.width, viewportSize.height));
+    webViewImpl->mainFrame()->setScrollOffset(scrollOffset);
+    ASSERT_EQ(scrollOffset, webViewImpl->mainFrame()->scrollOffset());

[aelias_OOO_until_Jul13, 2013/04/08 04:24:52]

Delete this assert.

[jdduke (slow), 2013/04/10 16:58:19]

Done.

+
+    WebCore::IntPoint anchorPoint = WebCore::IntPoint(scrollOffset) + WebCore::IntPoint(viewportSize.width / 2, 0);
+    RefPtr<WebCore::Node> anchorNode
+        = webViewImpl->mainFrameImpl()->frame()->eventHandler()->hitTestResultAtPoint(anchorPoint).innerNode();
+    ASSERT(anchorNode);
+
+    const WebCore::FloatSize preResizeRelativeOffset
+        = computeRelativeOffset(anchorPoint, anchorNode->Node::boundingBox());
+    webViewImpl->resize(WebSize(viewportSize.height, viewportSize.width));
+    WebCore::IntPoint newAnchorPoint = WebCore::IntPoint(webViewImpl->mainFrame()->scrollOffset()) + WebCore::IntPoint(viewportSize.height / 2, 0);
+    const WebCore::FloatSize postResizeRelativeOffset
+        = computeRelativeOffset(newAnchorPoint, anchorNode->Node::boundingBox());

[aelias_OOO_until_Jul13, 2013/04/08 04:24:52]

anchorNode->boundingBox()

+    EXPECT_NEAR(preResizeRelativeOffset.width(), postResizeRelativeOffset.width(), 0.1f);
+}
 #endif
 
 TEST_F(WebFrameTest, pageScaleFactorScalesPaintClip)