Make compositor and blink talk in fractional scroll offset

Source/web/tests/ScrollingCoordinatorChromiumTest.cpp

Index: Source/web/tests/ScrollingCoordinatorChromiumTest.cpp
diff --git a/Source/web/tests/ScrollingCoordinatorChromiumTest.cpp b/Source/web/tests/ScrollingCoordinatorChromiumTest.cpp
index c6d46af9f77c5ab0a038a45046e86eae63239205..d5e412a5d29e90f67bc70e9a7cfd14a7e26885a4 100644
--- a/Source/web/tests/ScrollingCoordinatorChromiumTest.cpp
+++ b/Source/web/tests/ScrollingCoordinatorChromiumTest.cpp
@@ -462,7 +462,7 @@ TEST_F(ScrollingCoordinatorChromiumTest, rtlIframe)
     ASSERT_TRUE(webScrollLayer->scrollable());
 
     int expectedScrollPosition = 958 + (innerFrameView->verticalScrollbar()->isOverlayScrollbar() ? 0 : 15);

[Rick Byers, 2014/10/04 00:04:25]

again, let's use a non-integer value

[Yufeng Shen (Slow to review), 2014/10/06 17:54:58]

hmm, not sure about this one. This test is testing the behavior that
the rtl page is scrolled to the rightmost upon layout, there is no actual
scrolling happening and the number is derived from the width/height of
frame/iframe.

[Rick Byers, 2014/10/06 21:11:30]

Ah, I hadn't looked that deeply.  Looks fine - thanks.

-    ASSERT_EQ(expectedScrollPosition, webScrollLayer->scrollPosition().x);
+    ASSERT_EQ(expectedScrollPosition, webScrollLayer->scrollPositionDouble().x);
 }
 
 TEST_F(ScrollingCoordinatorChromiumTest, setupScrollbarLayerShouldNotCrash)