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

cc/trees/layer_tree_host_unittest_scroll.cc

Index: cc/trees/layer_tree_host_unittest_scroll.cc
diff --git a/cc/trees/layer_tree_host_unittest_scroll.cc b/cc/trees/layer_tree_host_unittest_scroll.cc
index 59fbfb6a4f9632c9da3e1f7627aa0f60e6902672..8cb13e9f237b42fafe6274633903fd1fbf426be0 100644
--- a/cc/trees/layer_tree_host_unittest_scroll.cc
+++ b/cc/trees/layer_tree_host_unittest_scroll.cc
@@ -147,7 +147,7 @@ class LayerTreeHostScrollTestScrollSimple : public LayerTreeHostScrollTest {
     }
   }
 
-  void DidScrollOuterViewport() { num_scrolls_++; }
+  void DidScrollOuterViewport(const gfx::ScrollOffset&) { num_scrolls_++; }
 
   void AfterTest() override { EXPECT_EQ(1, num_scrolls_); }
 
@@ -230,7 +230,7 @@ class LayerTreeHostScrollTestScrollMultipleRedraw
     }
   }
 
-  void DidScrollOuterViewport() { num_scrolls_++; }
+  void DidScrollOuterViewport(const gfx::ScrollOffset&) { num_scrolls_++; }
 
   void AfterTest() override { EXPECT_EQ(1, num_scrolls_); }
 
@@ -412,7 +412,7 @@ class LayerTreeHostScrollTestScrollAbortedCommit
     }
   }
 
-  void DidScrollOuterViewport() { num_impl_scrolls_++; }
+  void DidScrollOuterViewport(const gfx::ScrollOffset&) { num_impl_scrolls_++; }
 
   void AfterTest() override {
     EXPECT_EQ(3, num_impl_scrolls_);
@@ -630,11 +630,12 @@ class LayerTreeHostScrollTestCaseWithChild : public LayerTreeHostScrollTest {
     }
   }
 
-  void DidScroll() {
+  void DidScroll(const gfx::ScrollOffset& offset) {
     final_scroll_offset_ = expected_scroll_layer_->scroll_offset();
+    EXPECT_VECTOR_EQ(offset, final_scroll_offset_);
   }
 
-  void DidScrollOuterViewport() { num_scrolls_++; }
+  void DidScrollOuterViewport(const gfx::ScrollOffset&) { num_scrolls_++; }
 
   void UpdateLayerTreeHost() override {
     EXPECT_VECTOR_EQ(gfx::Vector2d(),
@@ -923,7 +924,7 @@ class LayerTreeHostScrollTestSimple : public LayerTreeHostScrollTest {
     }
   }
 
-  void DidScrollOuterViewport() { num_scrolls_++; }
+  void DidScrollOuterViewport(const gfx::ScrollOffset&) { num_scrolls_++; }
 
   void AfterTest() override { EXPECT_EQ(1, num_scrolls_); }
 
@@ -1420,9 +1421,7 @@ class LayerTreeHostScrollTestLayerStructureChange
  protected:
   class FakeLayerScrollClient {
    public:
-    void DidScroll() {
-      owner_->DidScroll(layer_);
-    }
+    void DidScroll(const gfx::ScrollOffset&) { owner_->DidScroll(layer_); }
     LayerTreeHostScrollTestLayerStructureChange* owner_;
     Layer* layer_;
   };
@@ -1572,7 +1571,7 @@ class LayerTreeHostScrollTestScrollMFBA : public LayerTreeHostScrollTest {
     }
   }
 
-  void DidScrollOuterViewport() { num_scrolls_++; }
+  void DidScrollOuterViewport(const gfx::ScrollOffset&) { num_scrolls_++; }
 
   void AfterTest() override {
     EXPECT_EQ(3, num_commits_);
@@ -1791,7 +1790,7 @@ class LayerTreeHostScrollTestScrollAbortedCommitMFBA
     num_draws_++;
   }
 
-  void DidScrollOuterViewport() { num_impl_scrolls_++; }
+  void DidScrollOuterViewport(const gfx::ScrollOffset&) { num_impl_scrolls_++; }
 
   void AfterTest() override {
     EXPECT_EQ(3, num_impl_scrolls_);