Remove CSS regions support, keeping a bare minimum to support "region-based" multicol.

Remove CSS regions support, keeping a bare minimum to support "region-based" multicol.

Remove everything strictly specific to CSS regions, but keep the parts that
"region-based" multicol needs. So the render flow thread framework is still around,
albeit heavily trimmed down. RenderRegion has also been kept, but is now obviously
a misnomer (to be fixed later). It serves as a base class for what css3-break refers
to as a "fragmentainer" (e.g. column, page or region). Not sure if it should really
be a renderer type, seeing that these need to be created during layout (which should
be avoided for renderers). A fragmentainer is more akin to what a line box represents
than to what a renderer does.

Additional removal and cleanup is possible, but let's start with this.

BUG=none

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=167275

[mstensho (USE GERRIT), 2014-02-12 10:15:58]

Depends on https://codereview.chromium.org/159933010/ (removal of CSS regions
tests)

[lushnikov, 2014-02-13 17:14:35]

On 2014/02/12 10:15:58, Morten Stenshorne wrote:
> Depends on https://codereview.chromium.org/159933010/ (removal of CSS regions
> tests)

Hi Morten,

I proof-checked DevTools changes via creating a patch to remove CSS Regions from
DevTools only:
https://codereview.chromium.org/163413005/

It mostly matches your changes, but still have couple more lines deleted, so I
suggest landing it first.

https://codereview.chromium.org/134473008/diff/1/Source/devtools/Inspector-1....
File Source/devtools/Inspector-1.1.json (left):

https://codereview.chromium.org/134473008/diff/1/Source/devtools/Inspector-1....
Source/devtools/Inspector-1.1.json:2520: "id": "Region",
Could you please leave Inspector-1.1.json untouched as this is a freezed version
of protocol?

[mstensho (USE GERRIT), 2014-02-13 20:23:27]

Sure, go ahead and land https://codereview.chromium.org/163413005/ first.

https://codereview.chromium.org/134473008/diff/1/Source/devtools/Inspector-1....
File Source/devtools/Inspector-1.1.json (left):

https://codereview.chromium.org/134473008/diff/1/Source/devtools/Inspector-1....
Source/devtools/Inspector-1.1.json:2520: "id": "Region",
On 2014/02/13 17:14:36, lushnikov wrote:
> Could you please leave Inspector-1.1.json untouched as this is a freezed
version
> of protocol?

Done.

[eseidel, 2014-02-14 11:44:21]

lgtm

Wow.  Such a huge feature.  Thank you for working on this.  I would have had
trouble removing regions w/o killing multi-column too.

https://codereview.chromium.org/134473008/diff/80001/Source/core/dom/Node.h
File Source/core/dom/Node.h (right):

https://codereview.chromium.org/134473008/diff/80001/Source/core/dom/Node.h#n...
Source/core/dom/Node.h:719: NeedsStyleInvalidation = 1 << 29,
I probably wouldn't have bothered to re-sort these and just left bit 18 open
with a comment. :)

https://codereview.chromium.org/134473008/diff/80001/Source/core/frame/UseCou...
File Source/core/frame/UseCounter.cpp (left):

https://codereview.chromium.org/134473008/diff/80001/Source/core/frame/UseCou...
Source/core/frame/UseCounter.cpp:387: case CSSPropertyWebkitFlowInto: return
340;
I'm not sure if we remove these or just comment them out.  We can't ever reuse
these values.

[commit-bot: I haz the power, 2014-02-14 11:44:42]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mstensho@opera.com/134473008/80001

[eseidel, 2014-02-14 11:44:49]

The CQ bit was unchecked by eseidel@chromium.org

[commit-bot: I haz the power, 2014-02-14 11:45:24]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-02-14 11:45:25]

Failed to apply patch for Source/core/dom/Document.cpp:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file Source/core/dom/Document.cpp
  Hunk #3 FAILED at 1035.
  1 out of 3 hunks FAILED -- saving rejects to file
Source/core/dom/Document.cpp.rej

Patch:       Source/core/dom/Document.cpp
Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index
87d874a1b19f9ca108cde106e3fe8344f7202af0..cd5151cdc64d86f4691f5a7f7cfa32bd860b026c
100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -62,7 +62,6 @@
 #include "core/dom/Comment.h"
 #include "core/dom/ContextFeatures.h"
 #include "core/dom/DOMImplementation.h"
-#include "core/dom/DOMNamedFlowCollection.h"
 #include "core/dom/DocumentFragment.h"
 #include "core/dom/DocumentLifecycleNotifier.h"
 #include "core/dom/DocumentLifecycleObserver.h"
@@ -75,7 +74,6 @@
 #include "core/dom/ExecutionContextTask.h"
 #include "core/dom/MainThreadTaskRunner.h"
 #include "core/dom/MutationObserver.h"
-#include "core/dom/NamedFlowCollection.h"
 #include "core/dom/NodeChildRemovalTracker.h"
 #include "core/dom/NodeFilter.h"
 #include "core/dom/NodeIterator.h"
@@ -1037,24 +1035,6 @@ bool Document::regionBasedColumnsEnabled() const
     return settings() && settings()->regionBasedColumnsEnabled();
 }
 
-PassRefPtr<DOMNamedFlowCollection> Document::webkitGetNamedFlows()
-{
-    if (!RuntimeEnabledFeatures::cssRegionsEnabled() || !renderView())
-        return 0;
-
-    updateStyleIfNeeded();
-
-    return namedFlows()->createCSSOMSnapshot();
-}
-
-NamedFlowCollection* Document::namedFlows()
-{
-    if (!m_namedFlows)
-        m_namedFlows = NamedFlowCollection::create(this);
-
-    return m_namedFlows.get();
-}
-
 PassRefPtr<Element> Document::createElementNS(const AtomicString& namespaceURI,
const AtomicString& qualifiedName, ExceptionState& exceptionState)
 {
     AtomicString prefix, localName;

[mstensho (USE GERRIT), 2014-02-14 12:06:11]

Waiting for https://codereview.chromium.org/163413005/ to land.

https://codereview.chromium.org/134473008/diff/80001/Source/core/dom/Node.h
File Source/core/dom/Node.h (right):

https://codereview.chromium.org/134473008/diff/80001/Source/core/dom/Node.h#n...
Source/core/dom/Node.h:719: NeedsStyleInvalidation = 1 << 29,
On 2014/02/14 11:44:23, eseidel wrote:
> I probably wouldn't have bothered to re-sort these and just left bit 18 open
> with a comment. :)

Done.

https://codereview.chromium.org/134473008/diff/80001/Source/core/frame/UseCou...
File Source/core/frame/UseCounter.cpp (left):

https://codereview.chromium.org/134473008/diff/80001/Source/core/frame/UseCou...
Source/core/frame/UseCounter.cpp:387: case CSSPropertyWebkitFlowInto: return
340;
On 2014/02/14 11:44:23, eseidel wrote:
> I'm not sure if we remove these or just comment them out.  We can't ever reuse
> these values.

Done.

[lushnikov, 2014-02-14 14:50:55]

On 2014/02/14 12:06:11, Morten Stenshorne wrote:
> Waiting for https://codereview.chromium.org/163413005/ to land.
> 
> https://codereview.chromium.org/134473008/diff/80001/Source/core/dom/Node.h
> File Source/core/dom/Node.h (right):
> 
>
https://codereview.chromium.org/134473008/diff/80001/Source/core/dom/Node.h#n...
> Source/core/dom/Node.h:719: NeedsStyleInvalidation = 1 << 29,
> On 2014/02/14 11:44:23, eseidel wrote:
> > I probably wouldn't have bothered to re-sort these and just left bit 18 open
> > with a comment. :)
> 
> Done.
> 
>
https://codereview.chromium.org/134473008/diff/80001/Source/core/frame/UseCou...
> File Source/core/frame/UseCounter.cpp (left):
> 
>
https://codereview.chromium.org/134473008/diff/80001/Source/core/frame/UseCou...
> Source/core/frame/UseCounter.cpp:387: case CSSPropertyWebkitFlowInto: return
> 340;
> On 2014/02/14 11:44:23, eseidel wrote:
> > I'm not sure if we remove these or just comment them out.  We can't ever
reuse
> > these values.
> 
> Done.

https://codereview.chromium.org/163413005/ just landed.

[mstensho (USE GERRIT), 2014-02-14 15:12:28]

The CQ bit was checked by mstensho@opera.com

[commit-bot: I haz the power, 2014-02-14 15:12:43]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mstensho@opera.com/134473008/220001

[commit-bot: I haz the power, 2014-02-14 19:02:56]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-02-14 19:02:57]

Retried try job too often on win_blink_rel for step(s) webkit_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win_blink_...

[mstensho (USE GERRIT), 2014-02-14 20:08:38]

The CQ bit was checked by mstensho@opera.com

[commit-bot: I haz the power, 2014-02-14 20:08:56]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mstensho@opera.com/134473008/220001

[commit-bot: I haz the power, 2014-02-14 20:09:39]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-02-14 20:09:40]

Failed to apply patch for Source/core/rendering/RenderRegion.cpp:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file Source/core/rendering/RenderRegion.cpp
  Hunk #9 FAILED at 171.
  1 out of 12 hunks FAILED -- saving rejects to file
Source/core/rendering/RenderRegion.cpp.rej

Patch:       Source/core/rendering/RenderRegion.cpp
Index: Source/core/rendering/RenderRegion.cpp
diff --git a/Source/core/rendering/RenderRegion.cpp
b/Source/core/rendering/RenderRegion.cpp
index
d042526db3a479187e18e444e63e21001559c180..36a6b5858f955c85015e76cc164a56bd98bba309
100644
--- a/Source/core/rendering/RenderRegion.cpp
+++ b/Source/core/rendering/RenderRegion.cpp
@@ -34,8 +34,7 @@
 #include "core/rendering/FlowThreadController.h"
 #include "core/rendering/HitTestLocation.h"
 #include "core/rendering/PaintInfo.h"
-#include "core/rendering/RenderBoxRegionInfo.h"
-#include "core/rendering/RenderNamedFlowThread.h"
+#include "core/rendering/RenderFlowThread.h"
 #include "core/rendering/RenderView.h"
 
 using namespace std;
@@ -45,11 +44,7 @@ namespace WebCore {
 RenderRegion::RenderRegion(Element* element, RenderFlowThread* flowThread)
     : RenderBlockFlow(element)
     , m_flowThread(flowThread)
-    , m_parentNamedFlowThread(0)
-    , m_computedAutoHeight(-1)
     , m_isValid(false)
-    , m_hasCustomRegionStyle(false)
-    , m_hasAutoLogicalHeight(false)
 {
 }
 
@@ -62,29 +57,12 @@ LayoutUnit RenderRegion::pageLogicalWidth() const
 LayoutUnit RenderRegion::pageLogicalHeight() const
 {
     ASSERT(m_flowThread);
-    if (hasComputedAutoHeight() && !m_flowThread->inConstrainedLayoutPhase()) {
-        ASSERT(hasAutoLogicalHeight());
-        return computedAutoHeight();
-    }
     return m_flowThread->isHorizontalWritingMode() ? contentHeight() :
contentWidth();
 }
 
-// This method returns the maximum page size of a region with auto-height. This
is the initial
-// height value for auto-height regions in the first layout phase of the parent
named flow.
-LayoutUnit RenderRegion::maxPageLogicalHeight() const
-{
-    ASSERT(m_flowThread);
-    ASSERT(hasAutoLogicalHeight() &&
!m_flowThread->inConstrainedLayoutPhase());
-    return style()->logicalMaxHeight().isUndefined() ?
RenderFlowThread::maxLogicalHeight() :
computeReplacedLogicalHeightUsing(style()->logicalMaxHeight());
-}
-
 LayoutUnit RenderRegion::logicalHeightOfAllFlowThreadContent() const
 {
     ASSERT(m_flowThread);
-    if (hasComputedAutoHeight() && !m_flowThread->inConstrainedLayoutPhase()) {
-        ASSERT(hasAutoLogicalHeight());
-        return computedAutoHeight();
-    }
     return m_flowThread->isHorizontalWritingMode() ? contentHeight() :
contentWidth();
 }
 
@@ -97,8 +75,7 @@ LayoutRect
RenderRegion::overflowRectForFlowThreadPortion(const LayoutRect& flow
 {
     ASSERT(isValid());
 
-    bool isLastRegionWithRegionFragmentBreak = (isLastPortion &&
(style()->regionFragment() == BreakRegionFragment));
-    if (hasOverflowClip() || isLastRegionWithRegionFragmentBreak)
+    if (hasOverflowClip())
         return flowThreadPortionRect;
 
     LayoutRect flowThreadOverflow = m_flowThread->visualOverflowRect();
@@ -123,26 +100,6 @@ LayoutRect
RenderRegion::overflowRectForFlowThreadPortion(const LayoutRect& flow
     return clipRect;
 }
 
-RegionOversetState RenderRegion::regionOversetState() const
-{
-    if (isValid() && element())
-        return element()->regionOversetState();
-
-    return RegionUndefined;
-}
-
-void RenderRegion::setRegionOversetState(RegionOversetState state)
-{
-    if (element())
-        element()->setRegionOversetState(state);
-}
-
-Element* RenderRegion::element() const
-{
-    ASSERT(nodeForRegion() && nodeForRegion()->isElementNode());
-    return toElement(nodeForRegion());
-}
-
 LayoutUnit RenderRegion::pageLogicalTopForOffset(LayoutUnit /* offset */) const
 {
     return flowThread()->isHorizontalWritingMode() ?
flowThreadPortionRect().y() : flowThreadPortionRect().x();
@@ -162,148 +119,10 @@ bool RenderRegion::isLastRegion() const
     return m_flowThread->lastRegion() == this;
 }
 
-static bool shouldPaintRegionContentsInPhase(PaintPhase phase)
-{
-    return phase == PaintPhaseForeground
-        || phase == PaintPhaseSelection
-        || phase == PaintPhaseTextClip;
-}
-
-void RenderRegion::paintObject(PaintInfo& paintInfo, const LayoutPoint&
paintOffset)
-{
-    if (style()->visibility() != VISIBLE)
-        return;
-
-    RenderBlock::paintObject(paintInfo, paintOffset);
-
-    if (!isValid())
-        return;
-
-    // Delegate painting of content in region to RenderFlowThread.
-    // RenderFlowThread is a self painting layer (being a positioned object)
who is painting its children, the collected objects.
-    // Since we do not want to paint the flow thread content multiple times
(for each painting phase of the region object),
-    // we allow the flow thread painting only in certain phases.
-    if (!shouldPaintRegionContentsInPhase(paintInfo.phase))
-        return;
-
-    setRegionObjectsRegionStyle();
-    m_flowThread->paintFlowThreadPortionInRegion(paintInfo, this,
flowThreadPortionRect(), flowThreadPortionOverflowRect(),
LayoutPoint(paintOffset.x() + borderLeft() + paddingLeft(), paintOffset.y() +
borderTop() + paddingTop()));
-    restoreRegionObjectsOriginalStyle();
-}
-
-// Hit Testing
-bool RenderRegion::hitTestFlowThreadContents(const HitTestRequest& request,
HitTestResult& result, const HitTestLocation& locationInContainer, const
LayoutPoint& accumulatedOffset, HitTestAction action)
-{
-    if (!isValid() || action != HitTestForeground)
-        return false;
-
-    LayoutRect boundsRect =
borderBoxRectInRegion(locationInContainer.region());
-    boundsRect.moveBy(accumulatedOffset);
-    if (visibleToHitTesting() && locationInContainer.intersects(boundsRect)) {
-        if (m_flowThread->hitTestFlowThreadPortionInRegion(this,
flowThreadPortionRect(), flowThreadPortionOverflowRect(), request, result,
-            locationInContainer, LayoutPoint(accumulatedOffset.x() +
borderLeft() + paddingLeft(), accumulatedOffset.y() + borderTop() +
paddingTop())))
-            return true;
-    }
-
-    return false;
-}
-
-void RenderRegion::checkRegionStyle()
-{
-    ASSERT(m_flowThread);
-    bool customRegionStyle = false;
-
-    // FIXME: Region styling doesn't work for pseudo elements.
-    if (isElementBasedRegion())
-        customRegionStyle =
view()->document().ensureStyleResolver().checkRegionStyle(this->element());
-
-    setHasCustomRegionStyle(customRegionStyle);
-    m_flowThread->checkRegionsWithStyling();
-}
-
-void RenderRegion::incrementAutoLogicalHeightCount()
-{
-    ASSERT(isValid());
-    ASSERT(m_hasAutoLogicalHeight);
-
-    m_flowThread->incrementAutoLogicalHeightRegions();
-}
-
-void RenderRegion::decrementAutoLogicalHeightCount()
-{
-    ASSERT(isValid());
-
-    m_flowThread->decrementAutoLogicalHeightRegions();
-}
-
-void RenderRegion::updateRegionHasAutoLogicalHeightFlag()
-{
-    ASSERT(m_flowThread);
-
-    if (!isValid())
-        return;
-
-    bool didHaveAutoLogicalHeight = m_hasAutoLogicalHeight;
-    m_hasAutoLogicalHeight = shouldHaveAutoLogicalHeight();
-    if (m_hasAutoLogicalHeight != didHaveAutoLogicalHeight) {
-        if (m_hasAutoLogicalHeight) {
-            incrementAutoLogicalHeightCount();
-        } else {
-            clearComputedAutoHeight();
-            decrementAutoLogicalHeightCount();
-        }
-    }
-}
-
-bool RenderRegion::shouldHaveAutoLogicalHeight() const
-{
-    bool hasSpecifiedEndpointsForHeight = style()->logicalTop().isSpecified()
&& style()->logicalBottom().isSpecified();
-    bool hasAnchoredEndpointsForHeight = isOutOfFlowPositioned() &&
hasSpecifiedEndpointsForHeight;
-    bool hasAutoHeightStyle = style()->logicalHeight().isAuto() ||
style()->logicalHeight().isFitContent()
-        || style()->logicalHeight().isMaxContent() ||
style()->logicalHeight().isMinContent();
-    return hasAutoHeightStyle && !hasAnchoredEndpointsForHeight;
-}
-
-void RenderRegion::styleDidChange(StyleDifference diff, const RenderStyle*
oldStyle)
-{
-    RenderBlock::styleDidChange(diff, oldStyle);
-
-    // If the region is not attached to any thread, there is no need to check
-    // whether the region has region styling since no content will be displayed
-    // into the region.
-    if (!m_flowThread) {
-        setHasCustomRegionStyle(false);
-        return;
-    }
-
-    checkRegionStyle();
-    updateRegionHasAutoLogicalHeightFlag();
-
-    if (oldStyle && oldStyle->writingMode() != style()->writingMode())
-        m_flowThread->regionChangedWritingMode(this);
-}
-
 void RenderRegion::layoutBlock(bool relayoutChildren)
 {
     RenderBlockFlow::layoutBlock(relayoutChildren);
 
-    if (isValid()) {
-        LayoutRect oldRegionRect(flowThreadPortionRect());
-        if (!isHorizontalWritingMode())
-            oldRegionRect = oldRegionRect.transposedRect();
-
-        if (hasAutoLogicalHeight() &&
!m_flowThread->inConstrainedLayoutPhase()) {
-            m_flowThread->invalidateRegions();
-            clearComputedAutoHeight();
-            return;
-        }
-
-        if (!isRenderRegionSet() && (oldRegionRect.width() !=
pageLogicalWidth() || oldRegionRect.height() != pageLogicalHeight())) {
-            // This can happen even if we are in the inConstrainedLayoutPhase
and it will trigger a pathological layout of the flow thread.
-            m_flowThread->invalidateRegions();
-        }
-    }
-
     // FIXME: We need to find a way to set up overflow properly. Our flow
thread hasn't gotten a layout
     // yet, so we can't look to it for correct information. It's possible we
could wait until after the RenderFlowThread
     // gets a layout, and then try to propagate overflow information back to
the region, and then mark for a second layout.
@@ -312,8 +131,6 @@ void RenderRegion::layoutBlock(bool relayoutChildren)
     // The big problem though is that overflow needs to be region-specific. We
can't simply…
(message too large)

[mstensho (USE GERRIT), 2014-02-17 09:12:51]

The CQ bit was checked by mstensho@opera.com

[commit-bot: I haz the power, 2014-02-17 09:12:59]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mstensho@opera.com/134473008/540001

[commit-bot: I haz the power, 2014-02-17 11:29:03]

Change committed as 167275