Remove GraphicsLayer::didScroll and directly call ScrollableArea::didScroll

third_party/WebKit/Source/platform/graphics/GraphicsLayerTest.cpp

Index: third_party/WebKit/Source/platform/graphics/GraphicsLayerTest.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/GraphicsLayerTest.cpp b/third_party/WebKit/Source/platform/graphics/GraphicsLayerTest.cpp
index 08c88645d8e095511f00f58c4e37968e6eb164f1..871b6197f73fef5b98ca515608be9ce13e4c295a 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsLayerTest.cpp
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsLayerTest.cpp
@@ -210,7 +210,7 @@ TEST_F(GraphicsLayerTest, applyScrollToScrollableArea) {
 
   WebDoublePoint scrollPosition(7, 9);
   m_platformLayer->setScrollPositionDouble(scrollPosition);

[wkorman, 2017/02/07 22:18:05]

Do we still need to do this? It looks like this was set so that it could be
pulled off in GraphicsLayer.cpp:1166 above, but since now we pass it in below...
do we still need to set it here? Maybe there was some other reason for the
indirection?

I see this test is checking it in 215/216 below but with this change the test
case passes but maybe is just no longer relevant and the test case should just
be removed?

Anyway the only other remaining use of setScrollPositionDouble after this
change, outside of tests, looks like it's in
ScrollingCoordinator::scrollableAreaScrollLayerDidChange. And the only
getter-accessor use of it is in GraphicsLayer::didScroll() which you removed
above, so maybe we don't need the scrollPositionDouble field/accessors at all
any more.

[pdr., 2017/02/08 03:53:55]

Good catch, these are no longer needed.
We still need this setter for the ScrollingCoordinator case, as it forwards the
offset to the cc::Layer. The getter is only used in tests but it's for the same
reason. That said, the double-specific getter/setter isn't useful since we have
floats on both sides. I've updated the API to use floats (FloatPoint
scrollPosition(), setScrollPosition(FloatPoint)).

-  m_graphicsLayer->didScroll();
+  scrollableArea->didScroll(gfx::ScrollOffset(7, 9));
 
   EXPECT_FLOAT_EQ(scrollPosition.x, scrollableArea->getScrollOffset().width());
   EXPECT_FLOAT_EQ(scrollPosition.y, scrollableArea->getScrollOffset().height());