Remove scroll distribution code from Layer/LayerTreeHost.

cc/trees/layer_tree_host.cc

 // Copyright 2011 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 "cc/trees/layer_tree_host.h"
 
 #include <algorithm>
 #include <stack>
 #include <string>
 
@@ skipping 1041 matching lines @@
           outer_viewport_scroll_delta);
     }
     ApplyPageScaleDeltaFromImplSide(info.page_scale_delta);
 
     client_->ApplyScrollAndScale(
         inner_viewport_scroll_delta + outer_viewport_scroll_delta,
         info.page_scale_delta);
   }
 }
 
-gfx::Vector2d LayerTreeHost::DistributeScrollOffsetToViewports(
-    const gfx::Vector2d offset,
-    Layer* layer) {
-  DCHECK(layer);
-  if (layer != outer_viewport_scroll_layer_.get())
-    return offset;
-
-  gfx::Vector2d inner_viewport_offset =
-      inner_viewport_scroll_layer_->scroll_offset();
-  gfx::Vector2d outer_viewport_offset =
-      outer_viewport_scroll_layer_->scroll_offset();
-
-  if (offset == inner_viewport_offset + outer_viewport_offset) {
-    // In this case, nothing should change, so we just return to the outer
-    // viewport the offset is already has.
-    return outer_viewport_offset;
-  }
-
-  // In the spirit of document-scrolls-first, we always want any change to
-  // go to the outer viewport first.
-  gfx::Vector2d max_outer_viewport_scroll_offset =
-      outer_viewport_scroll_layer_->MaxScrollOffset();
-  gfx::Vector2d max_inner_viewport_scroll_offset =
-      inner_viewport_scroll_layer_->MaxScrollOffset();
-
-  // TODO(bokan): This trips on zoom-out due to how Blink orders scale-scroll.
-  //              Disabled until that's sorted out: crbug.com/336574
-  // gfx::Vector2d total_max_scroll_offset =
-  //    max_outer_viewport_scroll_offset + max_inner_viewport_scroll_offset;
-  // DCHECK(total_max_scroll_offset.x() >= offset.x() &&
-  //       total_max_scroll_offset.y() >= offset.y());
-
-  outer_viewport_offset = offset - inner_viewport_offset;
-  outer_viewport_offset.SetToMin(max_outer_viewport_scroll_offset);
-  outer_viewport_offset.SetToMax(gfx::Vector2d());
-
-  inner_viewport_offset = offset - outer_viewport_offset;
-  inner_viewport_offset.SetToMin(max_inner_viewport_scroll_offset);
-  inner_viewport_offset.SetToMax(gfx::Vector2d());
-  inner_viewport_scroll_layer_->SetScrollOffset(inner_viewport_offset);
-
-  return outer_viewport_offset;
-}
-
 void LayerTreeHost::StartRateLimiter() {
   if (animating_)
     return;
 
   if (!rate_limit_timer_.IsRunning()) {
     rate_limit_timer_.Start(FROM_HERE,
                             base::TimeDelta(),
                             this,
                             &LayerTreeHost::RateLimit);
   }
@@ skipping 180 matching lines @@
   swap_promise_list_.push_back(swap_promise.Pass());
 }
 
 void LayerTreeHost::BreakSwapPromises(SwapPromise::DidNotSwapReason reason) {
   for (size_t i = 0; i < swap_promise_list_.size(); i++)
     swap_promise_list_[i]->DidNotSwap(reason);
   swap_promise_list_.clear();
 }
 
 }  // namespace cc