Revert 158386 - Revert 158362 - Support high DPI scrollbar on top level web frame.

BUG=141389
TEST=Run chrome with --force-device-scale-factor=2 --force-compositing-mode and verify that the top-level scrollbar is high dpi.

CC tests are known flaky: http://code.google.com/p/chromium/issues/detail?id=148490
Re-committing the CC change.

Review URL: https://chromiumcodereview.appspot.com/10909255

TBR=flackr@chromium.org
Review URL: https://codereview.chromium.org/10990004

TBR=avi@chromium.org
Review URL: https://codereview.chromium.org/10989003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@158398 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 52 insertions, 11 deletions

diff --git a/cc/CCLayerImpl.cpp b/cc/CCLayerImpl.cpp
index 84597c5..b59ddb4 100644
--- a/cc/CCLayerImpl.cpp
+++ b/cc/CCLayerImpl.cpp
@@ -224,6 +224,15 @@ CCInputHandlerClient::ScrollStatus CCLayerImpl::tryScroll(const IntPoint& viewpo
     return CCInputHandlerClient::ScrollStarted;
 }
 
+IntRect CCLayerImpl::layerRectToContentRect(const WebKit::WebRect& layerRect)
+{
+    float widthScale = static_cast<float>(contentBounds().width()) / bounds().width();
+    float heightScale = static_cast<float>(contentBounds().height()) / bounds().height();
+    FloatRect contentRect(layerRect.x, layerRect.y, layerRect.width, layerRect.height);
+    contentRect.scale(widthScale, heightScale);
+    return enclosingIntRect(contentRect);
+}
+
 std::string CCLayerImpl::indentString(int indent)
 {
     std::string str;
diff --git a/cc/CCLayerImpl.h b/cc/CCLayerImpl.h
index d5c903b..65e12f3 100644
--- a/cc/CCLayerImpl.h
+++ b/cc/CCLayerImpl.h
@@ -262,6 +262,8 @@ protected:
 
     void appendDebugBorderQuad(CCQuadSink&, const CCSharedQuadState*, CCAppendQuadsData&) const;
 
+    IntRect layerRectToContentRect(const WebKit::WebRect& layerRect);
+
     virtual void dumpLayerProperties(std::string*, int indent) const;
     static std::string indentString(int indent);
 
diff --git a/cc/CCScrollbarLayerImpl.cpp b/cc/CCScrollbarLayerImpl.cpp
index 63be4f5..dd4791f 100644
--- a/cc/CCScrollbarLayerImpl.cpp
+++ b/cc/CCScrollbarLayerImpl.cpp
@@ -79,7 +79,8 @@ void CCScrollbarLayerImpl::appendQuads(CCQuadSink& quadSink, CCAppendQuadsData&
     bool premultipledAlpha = false;
     bool flipped = false;
     FloatRect uvRect(0, 0, 1, 1);
-    IntRect boundsRect(IntPoint(), contentBounds());
+    IntRect boundsRect(IntPoint(), bounds());
+    IntRect contentBoundsRect(IntPoint(), contentBounds());
 
     CCSharedQuadState* sharedQuadState = quadSink.useSharedQuadState(createSharedQuadState());
     appendDebugBorderQuad(quadSink, sharedQuadState, appendQuadsData);
@@ -90,7 +91,7 @@ void CCScrollbarLayerImpl::appendQuads(CCQuadSink& quadSink, CCAppendQuadsData&
         thumbRect = WebRect();
 
     if (m_thumbResourceId && !thumbRect.isEmpty()) {
-        OwnPtr<CCTextureDrawQuad> quad = CCTextureDrawQuad::create(sharedQuadState, IntRect(thumbRect.x, thumbRect.y, thumbRect.width, thumbRect.height), m_thumbResourceId, premultipledAlpha, uvRect, flipped);
+        OwnPtr<CCTextureDrawQuad> quad = CCTextureDrawQuad::create(sharedQuadState, layerRectToContentRect(thumbRect), m_thumbResourceId, premultipledAlpha, uvRect, flipped);
         quad->setNeedsBlending();
         quadSink.append(quad.release(), appendQuadsData);
     }
@@ -100,12 +101,12 @@ void CCScrollbarLayerImpl::appendQuads(CCQuadSink& quadSink, CCAppendQuadsData&
 
     // We only paint the track in two parts if we were given a texture for the forward track part.
     if (m_foreTrackResourceId && !foreTrackRect.isEmpty())
-        quadSink.append(CCTextureDrawQuad::create(sharedQuadState, IntRect(foreTrackRect.x, foreTrackRect.y, foreTrackRect.width, foreTrackRect.height), m_foreTrackResourceId, premultipledAlpha, toUVRect(foreTrackRect, boundsRect), flipped), appendQuadsData);
+        quadSink.append(CCTextureDrawQuad::create(sharedQuadState, layerRectToContentRect(foreTrackRect), m_foreTrackResourceId, premultipledAlpha, toUVRect(foreTrackRect, boundsRect), flipped), appendQuadsData);
 
     // Order matters here: since the back track texture is being drawn to the entire contents rect, we must append it after the thumb and
     // fore track quads. The back track texture contains (and displays) the buttons.
-    if (!boundsRect.isEmpty())
-        quadSink.append(CCTextureDrawQuad::create(sharedQuadState, IntRect(boundsRect), m_backTrackResourceId, premultipledAlpha, uvRect, flipped), appendQuadsData);
+    if (!contentBoundsRect.isEmpty())
+        quadSink.append(CCTextureDrawQuad::create(sharedQuadState, IntRect(contentBoundsRect), m_backTrackResourceId, premultipledAlpha, uvRect, flipped), appendQuadsData);
 }
 
 void CCScrollbarLayerImpl::didLoseContext()
@@ -132,7 +133,7 @@ WebKit::WebPoint CCScrollbarLayerImpl::CCScrollbar::location() const
 
 WebKit::WebSize CCScrollbarLayerImpl::CCScrollbar::size() const
 {
-    return WebKit::WebSize(m_owner->contentBounds().width(), m_owner->contentBounds().height());
+    return WebKit::WebSize(m_owner->bounds().width(), m_owner->bounds().height());
 }
 
 bool CCScrollbarLayerImpl::CCScrollbar::enabled() const
diff --git a/cc/LayerChromium.cpp b/cc/LayerChromium.cpp
index b053403..a7db9fd 100644
--- a/cc/LayerChromium.cpp
+++ b/cc/LayerChromium.cpp
@@ -116,6 +116,15 @@ void LayerChromium::setNeedsCommit()
         m_layerTreeHost->setNeedsCommit();
 }
 
+IntRect LayerChromium::layerRectToContentRect(const WebKit::WebRect& layerRect)
+{
+    float widthScale = static_cast<float>(contentBounds().width()) / bounds().width();
+    float heightScale = static_cast<float>(contentBounds().height()) / bounds().height();
+    FloatRect contentRect(layerRect.x, layerRect.y, layerRect.width, layerRect.height);
+    contentRect.scale(widthScale, heightScale);
+    return enclosingIntRect(contentRect);
+}
+
 void LayerChromium::setParent(LayerChromium* layer)
 {
     ASSERT(!layer || !layer->hasAncestor(this));
@@ -622,6 +631,9 @@ void LayerChromium::setContentsScale(float contentsScale)
 
 void LayerChromium::setBoundsContainPageScale(bool boundsContainPageScale)
 {
+    for (size_t i = 0; i < m_children.size(); ++i)
+        m_children[i]->setBoundsContainPageScale(boundsContainPageScale);
+
     if (boundsContainPageScale == m_boundsContainPageScale)
         return;
 
diff --git a/cc/LayerChromium.h b/cc/LayerChromium.h
index 0e02cfd..fc7a6739 100644
--- a/cc/LayerChromium.h
+++ b/cc/LayerChromium.h
@@ -232,6 +232,7 @@ public:
     void setContentsScale(float);
 
     // When true, the layer's contents are not scaled by the current page scale factor.
+    // setBoundsContainPageScale recursively sets the value on all child layers.
     void setBoundsContainPageScale(bool);
     bool boundsContainPageScale() const { return m_boundsContainPageScale; }
 
@@ -273,6 +274,8 @@ protected:
 
     void setNeedsCommit();
 
+    IntRect layerRectToContentRect(const WebKit::WebRect& layerRect);
+
     // This flag is set when layer need repainting/updating.
     bool m_needsDisplay;
 
diff --git a/cc/ScrollbarLayerChromium.cpp b/cc/ScrollbarLayerChromium.cpp
index 80e36fb..614e0ee 100644
--- a/cc/ScrollbarLayerChromium.cpp
+++ b/cc/ScrollbarLayerChromium.cpp
@@ -131,6 +131,16 @@ private:
     WebKit::WebScrollbar::ScrollbarPart m_trackPart;
 };
 
+bool ScrollbarLayerChromium::needsContentsScale() const
+{
+    return true;
+}
+
+IntSize ScrollbarLayerChromium::contentBounds() const
+{
+    return IntSize(lroundf(bounds().width() * contentsScale()), lroundf(bounds().height() * contentsScale()));
+}
+
 class ScrollbarThumbPainter : public LayerPainterChromium {
     WTF_MAKE_NONCOPYABLE(ScrollbarThumbPainter);
 public:
@@ -213,8 +223,10 @@ void ScrollbarLayerChromium::updatePart(LayerTextureUpdater* painter, LayerTextu
         return;
 
     // Paint and upload the entire part.
+    float widthScale = static_cast<float>(contentBounds().width()) / bounds().width();
+    float heightScale = static_cast<float>(contentBounds().height()) / bounds().height();
     IntRect paintedOpaqueRect;
-    painter->prepareToUpdate(rect, rect.size(), 1, 1, paintedOpaqueRect, stats);
+    painter->prepareToUpdate(rect, rect.size(), widthScale, heightScale, paintedOpaqueRect, stats);
     texture->prepareRect(rect, stats);
 
     IntSize destOffset(0, 0);
@@ -240,8 +252,8 @@ void ScrollbarLayerChromium::setTexturePriorities(const CCPriorityCalculator&)
         m_foreTrack->texture()->setRequestPriority(CCPriorityCalculator::uiPriority(drawsToRoot));
     }
     if (m_thumb) {
-        WebKit::WebRect thumbRect = m_geometry->thumbRect(m_scrollbar.get());
-        m_thumb->texture()->setDimensions(IntSize(thumbRect.width, thumbRect.height), m_textureFormat);
+        IntSize thumbSize = layerRectToContentRect(m_geometry->thumbRect(m_scrollbar.get())).size();
+        m_thumb->texture()->setDimensions(thumbSize, m_textureFormat);
         m_thumb->texture()->setRequestPriority(CCPriorityCalculator::uiPriority(drawsToRoot));
     }
 }
@@ -254,14 +266,14 @@ void ScrollbarLayerChromium::update(CCTextureUpdateQueue& queue, const CCOcclusi
     createTextureUpdaterIfNeeded();
 
     IntPoint scrollbarOrigin(m_scrollbar->location().x, m_scrollbar->location().y);
-    IntRect contentRect(scrollbarOrigin, contentBounds());
+    IntRect contentRect = layerRectToContentRect(WebKit::WebRect(scrollbarOrigin.x(), scrollbarOrigin.y(), bounds().width(), bounds().height()));
     updatePart(m_backTrackUpdater.get(), m_backTrack.get(), contentRect, queue, stats);
     if (m_foreTrack && m_foreTrackUpdater)
         updatePart(m_foreTrackUpdater.get(), m_foreTrack.get(), contentRect, queue, stats);
 
     // Consider the thumb to be at the origin when painting.
     WebKit::WebRect thumbRect = m_geometry->thumbRect(m_scrollbar.get());
-    IntRect originThumbRect = IntRect(0, 0, thumbRect.width, thumbRect.height);
+    IntRect originThumbRect = layerRectToContentRect(WebKit::WebRect(0, 0, thumbRect.width, thumbRect.height));
     if (!originThumbRect.isEmpty())
         updatePart(m_thumbUpdater.get(), m_thumb.get(), originThumbRect, queue, stats);
 }
diff --git a/cc/ScrollbarLayerChromium.h b/cc/ScrollbarLayerChromium.h
index 62ace2d..236ba83 100644
--- a/cc/ScrollbarLayerChromium.h
+++ b/cc/ScrollbarLayerChromium.h
@@ -29,6 +29,8 @@ public:
     virtual ~ScrollbarLayerChromium();
 
     // LayerChromium interface
+    virtual bool needsContentsScale() const OVERRIDE;
+    virtual IntSize contentBounds() const OVERRIDE;
     virtual void setTexturePriorities(const CCPriorityCalculator&) OVERRIDE;
     virtual void update(CCTextureUpdateQueue&, const CCOcclusionTracker*, CCRenderingStats&) OVERRIDE;
     virtual void setLayerTreeHost(CCLayerTreeHost*) OVERRIDE;