Account for writing-mode flip of the composited element for interest rects.

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMappingTest.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/layout/compositing/CompositedLayerMapping.h"
 
 #include "core/frame/FrameView.h"
 #include "core/layout/LayoutBoxModelObject.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/LayoutView.h"
@@ skipping 91 matching lines @@
     document().view()->updateAllLifecyclePhases();
     Element* element = document().getElementById("target");
     PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
     ASSERT_TRUE(paintLayer->graphicsLayerBacking());
     ASSERT_TRUE(paintLayer->compositedLayerMapping());
     // recomputeInterestRect computes the interest rect; computeInterestRect applies the extra setting to paint everything.
     EXPECT_RECT_EQ(IntRect(0, 0, 200, 4592), recomputeInterestRect(paintLayer->graphicsLayerBacking()));
     EXPECT_RECT_EQ(IntRect(0, 0, 200, 10000), computeInterestRect(paintLayer->compositedLayerMapping(), paintLayer->graphicsLayerBacking(), IntRect()));
 }
 
+TEST_F(CompositedLayerMappingTest, VerticalRightLeftWritingModeDocument)
+{
+    setBodyInnerHTML("<style>html,body { margin: 0px } html { -webkit-writing-mode: vertical-rl}</style> <div id='target' style='width: 10000px; height: 200px;'></div>");
+
+    document().settings()->setMainFrameClipsContent(false);
+
+    document().view()->updateAllLifecyclePhases();
+    document().view()->scrollTo(DoublePoint(-5000, 0));
+    document().view()->updateAllLifecyclePhases();
+
+    PaintLayer* paintLayer = document().layoutView()->layer();
+    ASSERT_TRUE(paintLayer->graphicsLayerBacking());
+    ASSERT_TRUE(paintLayer->compositedLayerMapping());
+    // A scroll by -5000px is equivalent to a scroll by (10000 - 5000 - 800)px = 4200px in non-RTL mode. Expanding
+    // the resulting rect by 4000px in each direction yields this result.
+    EXPECT_RECT_EQ(IntRect(200, 0, 8800, 600), recomputeInterestRect(paintLayer->graphicsLayerBacking()));
+}
 
 TEST_F(CompositedLayerMappingTest, RotatedInterestRect)
 {
     setBodyInnerHTML(
         "<div id='target' style='width: 200px; height: 200px; will-change: transform; transform: rotateZ(45deg)'></div>");
 
     document().view()->updateAllLifecyclePhases();
     Element* element = document().getElementById("target");
     PaintLayer* paintLayer = toLayoutBoxModelObject(element->layoutObject())->layer();
     ASSERT_TRUE(!!paintLayer->graphicsLayerBacking());
@@ skipping 442 matching lines @@
     // Scroll 3000 pixels down to bring the scrollable area to somewhere in the middle.
     frameDocument.view()->setScrollPosition(DoublePoint(0.0, 3000.0), ProgrammaticScroll);
     document().view()->updateAllLifecyclePhases();
 
     ASSERT_TRUE(frameDocument.view()->layoutView()->hasLayer());
     // The width is 485 pixels due to the size of the scrollbar.
     EXPECT_RECT_EQ(IntRect(0, 0, 500, 7500), recomputeInterestRect(frameDocument.view()->layoutView()->enclosingLayer()->graphicsLayerBacking()));
 }
 
 } // namespace blink