Apply size constraints for direct compositing also to background images.

The fact that this was not done before led to a failed WebKit assertion
in the UIProcess which caused any WebView application loading pages
with large background images (e.g. flickr.com) to crash on Windows.

Task-number: QTBUG-35208
Change-Id: Ieae76e19fc08483cbd038a7c14e06b4bd12dd681
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@digia.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/Source/WebCore/rendering/RenderLayerBacking.cpp b/Source/WebCore/rendering/RenderLayerBacking.cpp
index 955315eef..143c7d32c 100644
--- a/Source/WebCore/rendering/RenderLayerBacking.cpp
+++ b/Source/WebCore/rendering/RenderLayerBacking.cpp
@@ -1447,6 +1447,14 @@ bool canCreateTiledImage(const RenderStyle* style)
     if (!image->isBitmapImage())
         return false;
 
+#if USE(COORDINATED_GRAPHICS)
+    // Direct compositing becomes slow when the images are too
+    // large and the UIProcess asserts if one of the dimensions
+    // is larger than 2000.
+    if (2000 < std::max(image->width(), image->height()))
+        return false;
+#endif
+
     return true;
 }