Paint scrollbars at device scale resolution.

BUG=531257

Review URL: https://codereview.chromium.org/1430503007

Cr-Commit-Position: refs/heads/master@{#358464}

3 files changed, 20 insertions, 6 deletions

diff --git a/third_party/WebKit/Source/core/page/scrolling/ScrollingCoordinator.cpp b/third_party/WebKit/Source/core/page/scrolling/ScrollingCoordinator.cpp
index f3b10cc..21d9172 100644
--- a/third_party/WebKit/Source/core/page/scrolling/ScrollingCoordinator.cpp
+++ b/third_party/WebKit/Source/core/page/scrolling/ScrollingCoordinator.cpp
@@ -276,10 +276,10 @@ void ScrollingCoordinator::removeWebScrollbarLayer(ScrollableArea* scrollableAre
         GraphicsLayer::unregisterContentsLayer(scrollbarLayer->layer());
 }
 
-static PassOwnPtr<WebScrollbarLayer> createScrollbarLayer(Scrollbar* scrollbar)
+static PassOwnPtr<WebScrollbarLayer> createScrollbarLayer(Scrollbar* scrollbar, float deviceScaleFactor)
 {
     ScrollbarTheme* theme = scrollbar->theme();
-    WebScrollbarThemePainter painter(theme, scrollbar);
+    WebScrollbarThemePainter painter(theme, scrollbar, deviceScaleFactor);
     OwnPtr<WebScrollbarThemeGeometry> geometry(WebScrollbarThemeGeometryNative::create(theme));
 
     OwnPtr<WebScrollbarLayer> scrollbarLayer = adoptPtr(Platform::current()->compositorSupport()->createScrollbarLayer(WebScrollbarImpl::create(scrollbar), painter, geometry.leakPtr()));
@@ -367,7 +367,7 @@ void ScrollingCoordinator::scrollableAreaScrollbarLayerDidChange(ScrollableArea*
                 ASSERT(RuntimeEnabledFeatures::overlayScrollbarsEnabled());
                 webScrollbarLayer = createSolidColorScrollbarLayer(orientation, scrollbar->theme()->thumbThickness(scrollbar), scrollbar->theme()->trackPosition(scrollbar), scrollableArea->shouldPlaceVerticalScrollbarOnLeft());
             } else {
-                webScrollbarLayer = createScrollbarLayer(scrollbar);
+                webScrollbarLayer = createScrollbarLayer(scrollbar, m_page->deviceScaleFactor());
             }
             scrollbarLayer = addWebScrollbarLayer(scrollableArea, orientation, webScrollbarLayer.release());
         }
diff --git a/third_party/WebKit/Source/platform/exported/WebScrollbarThemePainter.cpp b/third_party/WebKit/Source/platform/exported/WebScrollbarThemePainter.cpp
index deb9b6d..8b63bbf 100644
--- a/third_party/WebKit/Source/platform/exported/WebScrollbarThemePainter.cpp
+++ b/third_party/WebKit/Source/platform/exported/WebScrollbarThemePainter.cpp
@@ -41,6 +41,7 @@ void WebScrollbarThemePainter::assign(const WebScrollbarThemePainter& painter)
     // This is a pointer to a static object, so no ownership transferral.
     m_theme = painter.m_theme;
     m_scrollbar = painter.m_scrollbar;
+    m_deviceScaleFactor = painter.m_deviceScaleFactor;
 }
 
 void WebScrollbarThemePainter::reset()
@@ -55,6 +56,7 @@ void WebScrollbarThemePainter::paintScrollbarBackground(WebCanvas* canvas, const
 
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintScrollbarBackground(&pictureBuilder.context(), m_scrollbar.get());
     pictureBuilder.endRecording()->playback(canvas);
 }
@@ -63,6 +65,7 @@ void WebScrollbarThemePainter::paintTrackBackground(WebCanvas* canvas, const Web
 {
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintTrackBackground(&pictureBuilder.context(), m_scrollbar.get(), intRect);
     pictureBuilder.endRecording()->playback(canvas);
 }
@@ -71,6 +74,7 @@ void WebScrollbarThemePainter::paintBackTrackPart(WebCanvas* canvas, const WebRe
 {
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintTrackPiece(&pictureBuilder.context(), m_scrollbar.get(), intRect, BackTrackPart);
     pictureBuilder.endRecording()->playback(canvas);
 }
@@ -79,6 +83,7 @@ void WebScrollbarThemePainter::paintForwardTrackPart(WebCanvas* canvas, const We
 {
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintTrackPiece(&pictureBuilder.context(), m_scrollbar.get(), intRect, ForwardTrackPart);
     pictureBuilder.endRecording()->playback(canvas);
 }
@@ -87,6 +92,7 @@ void WebScrollbarThemePainter::paintBackButtonStart(WebCanvas* canvas, const Web
 {
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintButton(&pictureBuilder.context(), m_scrollbar.get(), intRect, BackButtonStartPart);
     pictureBuilder.endRecording()->playback(canvas);
 }
@@ -95,6 +101,7 @@ void WebScrollbarThemePainter::paintBackButtonEnd(WebCanvas* canvas, const WebRe
 {
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintButton(&pictureBuilder.context(), m_scrollbar.get(), intRect, BackButtonEndPart);
     pictureBuilder.endRecording()->playback(canvas);
 }
@@ -103,6 +110,7 @@ void WebScrollbarThemePainter::paintForwardButtonStart(WebCanvas* canvas, const
 {
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintButton(&pictureBuilder.context(), m_scrollbar.get(), intRect, ForwardButtonStartPart);
     pictureBuilder.endRecording()->playback(canvas);
 }
@@ -111,6 +119,7 @@ void WebScrollbarThemePainter::paintForwardButtonEnd(WebCanvas* canvas, const We
 {
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintButton(&pictureBuilder.context(), m_scrollbar.get(), intRect, ForwardButtonEndPart);
     pictureBuilder.endRecording()->playback(canvas);
 }
@@ -119,6 +128,7 @@ void WebScrollbarThemePainter::paintTickmarks(WebCanvas* canvas, const WebRect&
 {
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintTickmarks(&pictureBuilder.context(), m_scrollbar.get(), intRect);
     pictureBuilder.endRecording()->playback(canvas);
 }
@@ -127,13 +137,15 @@ void WebScrollbarThemePainter::paintThumb(WebCanvas* canvas, const WebRect& rect
 {
     IntRect intRect(rect);
     SkPictureBuilder pictureBuilder(intRect);
+    pictureBuilder.context().setDeviceScaleFactor(m_deviceScaleFactor);
     m_theme->paintThumb(&pictureBuilder.context(), m_scrollbar.get(), intRect);
     pictureBuilder.endRecording()->playback(canvas);
 }
 
-WebScrollbarThemePainter::WebScrollbarThemePainter(ScrollbarTheme* theme, Scrollbar* scrollbar)
+WebScrollbarThemePainter::WebScrollbarThemePainter(ScrollbarTheme* theme, Scrollbar* scrollbar, float deviceScaleFactor)
     : m_theme(theme)
     , m_scrollbar(scrollbar)
+    , m_deviceScaleFactor(deviceScaleFactor)
 {
 }
 
diff --git a/third_party/WebKit/public/platform/WebScrollbarThemePainter.h b/third_party/WebKit/public/platform/WebScrollbarThemePainter.h
index 268d94b..6563a6e 100644
--- a/third_party/WebKit/public/platform/WebScrollbarThemePainter.h
+++ b/third_party/WebKit/public/platform/WebScrollbarThemePainter.h
@@ -38,7 +38,7 @@ struct WebRect;
 
 class WebScrollbarThemePainter {
 public:
-    WebScrollbarThemePainter() : m_theme(0) { }
+    WebScrollbarThemePainter() : m_theme(0), m_deviceScaleFactor(1.0) { }
     WebScrollbarThemePainter(const WebScrollbarThemePainter& painter) { assign(painter); }
     virtual ~WebScrollbarThemePainter()
     {
@@ -65,7 +65,7 @@ public:
     BLINK_PLATFORM_EXPORT void paintThumb(WebCanvas*, const WebRect&);
 
 #if INSIDE_BLINK
-    BLINK_PLATFORM_EXPORT WebScrollbarThemePainter(ScrollbarTheme*, Scrollbar*);
+    BLINK_PLATFORM_EXPORT WebScrollbarThemePainter(ScrollbarTheme*, Scrollbar*, float deviceScaleFactor);
 #endif
 
 private:
@@ -80,6 +80,8 @@ private:
     // scrollbar (and not a WebScrollbar wrapper) due to static_casts for
     // LayoutScrollbar and pointer-based HashMap lookups for Lion scrollbars.
     WebPrivatePtr<Scrollbar> m_scrollbar;
+
+    float m_deviceScaleFactor;
 };
 
 } // namespace blink