Exclude cases of full repaint on viewport height change

Exclude cases of full repaint on viewport height change

We treat viewport as the background positioning area if background-
attachment is 'fixed' (otherwise the viewport is only the background
paiting area, not the background positioning area).

Added the condition to avoid full repaint if background is not fixed
or is composited.

BUG=258219
TEST=fast/repaint/window-resize-background-image-generated.html
TEST=fast/repaint/window-resize-background-image-non-fixed.html
TEST=fast/repaint/window-resize-background-image-fixed-centered-composited.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=175398

[Xianzhu, 2014-05-27 22:32:50]

Changes about the background repaint conditions have been separated into
https://codereview.chromium.org/306483011/.

This CL is now depending on that CL.

[Xianzhu, 2014-05-30 21:22:26]

On 2014/05/27 22:32:50, Xianzhu wrote:
> Changes about the background repaint conditions have been separated into
> https://codereview.chromium.org/306483011/.
> 
> This CL is now depending on that CL.

The depended CL has been in CQ. Could you PTAL this one?

[Xianzhu, 2014-06-03 17:17:12]

ping...

[esprehn, 2014-06-03 17:21:43]

lgtm

[commit-bot: I haz the power, 2014-06-03 17:22:01]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/wangxianzhu@chromium.org/293063016/20001

[commit-bot: I haz the power, 2014-06-03 17:22:11]

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

[commit-bot: I haz the power, 2014-06-03 17:22:11]

Failed to apply patch for Source/core/rendering/RenderView.cpp:
While running patch -p1 --forward --force --no-backup-if-mismatch;
  patching file Source/core/rendering/RenderView.cpp
  Hunk #1 FAILED at 201.
  1 out of 1 hunk FAILED -- saving rejects to file
Source/core/rendering/RenderView.cpp.rej

Patch:       Source/core/rendering/RenderView.cpp
Index: Source/core/rendering/RenderView.cpp
diff --git a/Source/core/rendering/RenderView.cpp
b/Source/core/rendering/RenderView.cpp
index
099458fe16de9df3002b9b595317f5acd58c9523..075d9df5c28cff8c425b9c2123acf2d000dcfa65
100644
--- a/Source/core/rendering/RenderView.cpp
+++ b/Source/core/rendering/RenderView.cpp
@@ -201,8 +201,15 @@ bool RenderView::shouldDoFullRepaintForNextLayout() const
 
     if (height() != viewHeight()) {
         if (RenderObject* backgroundRenderer = this->backgroundRenderer()) {
-            if
(backgroundRenderer->mustRepaintFillLayersOnHeightChange(style()->backgroundLayers()))
+            // When background-attachment is 'fixed', we treat the viewport
(instead of the 'root'
+            // i.e. html or body) as the background positioning area, and we
should full repaint
+            // viewport resize if the background image is not composited and
needs full repaint on
+            // background positioning area resize.
+            if (!m_compositor ||
!m_compositor->needsFixedRootBackgroundLayer(layer())) {
+                if (backgroundRenderer->style()->hasFixedBackgroundImage()
+                    &&
mustRepaintFillLayersOnHeightChange(backgroundRenderer->style()->backgroundLayers()))
                 return true;
+            }
         }
     }

[Xianzhu, 2014-06-03 17:44:10]

The CQ bit was checked by wangxianzhu@chromium.org

[commit-bot: I haz the power, 2014-06-03 17:44:34]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/wangxianzhu@chromium.org/293063016/40001

[commit-bot: I haz the power, 2014-06-03 18:49:46]

FYI, CQ is re-trying this CL (attempt #1).
The failing builders are:
  mac_gpu_retina_triggered_tests on tryserver.chromium.gpu
(http://build.chromium.org/p/tryserver.chromium.gpu/builders/mac_gpu_retina_tr...)

[commit-bot: I haz the power, 2014-06-03 19:23:47]

Change committed as 175398