Enabled using viewport on desktop browsers behind experimental flag

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 efd4b60e51d1e245c80d2aa75e669379b6862ab9..653ff819c76f67d9dd6faf9d1ca655e3bcdaa708 100644
--- a/Source/WebKit/chromium/src/WebViewImpl.cpp
+++ b/Source/WebKit/chromium/src/WebViewImpl.cpp
@@ -1605,7 +1605,11 @@ void WebViewImpl::resize(const WebSize& newSize)
 
     m_size = newSize;
 
-    bool shouldAnchorAndRescaleViewport = settings()->viewportEnabled() && oldSize.width && oldContentsWidth;
+    // On devices like phones where a resize comes from screen rotation, we want to
+    // adjust the viewport size so that we don't cause a relayout

[aelias_OOO_until_Jul13, 2013/06/18 01:24:18]

This comment doesn't accurately describe what this is doing: it isn't adjusting
the viewport size or avoiding any relayout.  We're adjusting the scroll position
and page scale to keep content onscreen.

+    bool shouldAnchorAndRescaleViewport = settings()->viewportEnabled()
+        && settings()->resizeAffectsLayoutWidth() && oldSize.width && oldContentsWidth;
+
     ViewportAnchor viewportAnchor(mainFrameImpl()->frame()->eventHandler());
     if (shouldAnchorAndRescaleViewport) {
         viewportAnchor.setAnchor(view->visibleContentRect(),
@@ -3019,7 +3023,12 @@ void WebViewImpl::updatePageDefinedPageScaleConstraints(const ViewportArguments&
         && layoutSize.width != fixedLayoutSize().width)
             page()->mainFrame()->document()->textAutosizer()->recalculateMultipliers();
 
-    setFixedLayoutSize(layoutSize);
+    // If layoutFallbackWidthIsWindowWidth is set and there's no viewport width set, set the layout size to the window size
+    if (settings()->layoutFallbackWidthIsWindowWidth() && arguments.width == ViewportArguments::ValueAuto)
+        setFixedLayoutSize(m_size);
+    else
+        setFixedLayoutSize(layoutSize);
+
 }
 
 IntSize WebViewImpl::contentsSize() const
@@ -3607,7 +3616,10 @@ void WebViewImpl::didCommitLoad(bool* isNewNavigation, bool isNavigationWithinPa
     m_newNavigationLoader = 0;
 #endif
     m_observedNewNavigation = false;
-    if (*isNewNavigation && !isNavigationWithinPage)
+
+    // FIXME: Always need reset when layoutFallbackWidthIsWindowWidth is set
+    // this is a hack to fix some page scaling issues when reloading a page. Why is this needed?

[aelias_OOO_until_Jul13, 2013/06/18 01:24:18]

Instead of doing this, try calling setInitialPageScaleOverride(1) from the
Chromium side and see if that fixes your problem.

[aelias_OOO_until_Jul13, 2013/06/18 01:30:19]

On second thought, that probably won't work.  I don't think this change is the
right fix, whatever the problem is.  You probably should add debug logging
locally to diagnose the issue further: sometimes page scale initialization gets
messed up due to subtle timing issues in when different sizes get initialized.

+    if ((*isNewNavigation && !isNavigationWithinPage) || settings()->layoutFallbackWidthIsWindowWidth())
         m_pageScaleConstraintsSet.setNeedsReset(true);
 
     // Make sure link highlight from previous page is cleared.