cc: Do not request redraw on commit when impl-side painting

cc/layer_tree_host_unittest_scroll.cc

Index: cc/layer_tree_host_unittest_scroll.cc
diff --git a/cc/layer_tree_host_unittest_scroll.cc b/cc/layer_tree_host_unittest_scroll.cc
index 5c30a22de8b5405d1d71ab8b25c4ca2574c72032..bfb5e5f2157f4274a5ae00d0a94443bfe7858925 100644
--- a/cc/layer_tree_host_unittest_scroll.cc
+++ b/cc/layer_tree_host_unittest_scroll.cc
@@ -537,6 +537,13 @@ class ImplSidePaintingScrollTestSimple : public ImplSidePaintingScrollTest {
     return can_activate_;
   }
 
+  virtual void commitCompleteOnThread(LayerTreeHostImpl* impl) OVERRIDE {
+    // We force a second draw here of the first commit before activating
+    // the second commit.
+    if (impl->activeTree()->source_frame_number() == 0)
+      impl->setNeedsRedraw();
+  }
+
   virtual void drawLayersOnThread(LayerTreeHostImpl* impl) OVERRIDE {
     ImplSidePaintingScrollTest::drawLayersOnThread(impl);
 
@@ -558,6 +565,9 @@ class ImplSidePaintingScrollTestSimple : public ImplSidePaintingScrollTest {
           EXPECT_VECTOR_EQ(root->scrollDelta(), impl_thread_scroll1_);
           EXPECT_VECTOR_EQ(root->sentScrollDelta(), gfx::Vector2d());
           postSetNeedsCommitToMainThread();
+
+          // commitCompleteOnThread will trigger this function again
+          // and cause us to take the else clause.
         } else {
           can_activate_ = true;
           ASSERT_TRUE(pending_root);