Changeset 182673 in webkit

Timestamp:

Apr 12, 2015, 1:28:44 PM (11 years ago)

Author:

Simon Fraser

Message:

Scrollbars in composited overflow and iframes fail to render on Mac
​https://bugs.webkit.org/show_bug.cgi?id=143647
rdar://problem/20340544

Reviewed by Darin Adler.

When adding support for drawing scrollbars on the scrolling thread, we inadvertently
disabled scrollbar drawing in other composited, main-thread scrolling configurations.

Fix by having Scrollbar::supportsUpdateOnSecondaryThread() only return true if
the scrollable area is using async scrolling.

Sadly, we can't layout-test this.

• platform/Scrollbar.cpp:

(WebCore::Scrollbar::supportsUpdateOnSecondaryThread):

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/Scrollbar.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2015-04-12  Simon Fraser  <simon.fraser@apple.com>
+
+        Scrollbars in composited overflow and iframes fail to render on Mac
+        https://bugs.webkit.org/show_bug.cgi?id=143647
+        rdar://problem/20340544
+
+        Reviewed by Darin Adler.
+
+        When adding support for drawing scrollbars on the scrolling thread, we inadvertently
+        disabled scrollbar drawing in other composited, main-thread scrolling configurations.
+        
+        Fix by having Scrollbar::supportsUpdateOnSecondaryThread() only return true if
+        the scrollable area is using async scrolling.
+        
+        Sadly, we can't layout-test this.
+
+        * platform/Scrollbar.cpp:
+        (WebCore::Scrollbar::supportsUpdateOnSecondaryThread):
+
 2015-04-12  Simon Fraser  <simon.fraser@apple.com>
 

trunk/Source/WebCore/platform/Scrollbar.cpp

@@ -531 +531 @@
 #if ENABLE(ASYNC_SCROLLING) && PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED >= 101000
     return !m_scrollableArea.forceUpdateScrollbarsOnMainThreadForPerformanceTesting()
-        && (m_scrollableArea.hasLayerForVerticalScrollbar() || m_scrollableArea.hasLayerForHorizontalScrollbar());
+        && (m_scrollableArea.hasLayerForVerticalScrollbar() || m_scrollableArea.hasLayerForHorizontalScrollbar())
+        && m_scrollableArea.usesAsyncScrolling();
 #else
     return false;