Revert of Pinch/Zoom Infrastructure & Plumbing CL (https://codereview.chromium.org/23983047/)

Reason for revert:
This patch broke several blink-side compositing/rtl tests[1][2]. It's
unclear whether these tests are valuable, given some comments
in TestExpectations, but since I know nothing about compositing
I'll leave the decision about what to do with these tests up to
someone who does.

[1]: http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=%40ToT%20Blink&tests=compositing/rtl/rtl-iframe-absolute-overflow-scrolled.html,compositing/rtl/rtl-iframe-absolute-overflow.html,compositing/rtl/rtl-iframe-fixed-overflow-scrolled.html,compositing/rtl/rtl-iframe-fixed-overflow.html
[2]: http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Mac10.7/builds/22131

Original issue's description:
> Pinch/Zoom Infrastructure & Plumbing CL
> 
> This CL supplies the necessary changes to CC to support the
> inner/outer viewport model for pinch-zoom and fixed-position 
> elements. The specification for these changes is contained in 
> the document "Layer-based Solution for Pinch Zoom / Fixed 
> Position".
> 
> It incorporates a change to how scrollbar parameters are 
> computed (removes the notion of max_scroll_offset as a 
> quantity set be the embedder, and instead inferred from the 
> relative sizes of a clip layer w.r.t. the scroll layer).
> 
> Scrollbars are generalized so that a layer may have more than 
> two scrollbars, and the parameters of the scrollbar are set 
> w.r.t. the sizes and positions of a clip and a scroll layer. 
> Further, changes to the scrip/scroll layer automatically 
> notify any attached scrollbars.
> 
> The CL also removes existing references to root_scroll_layer 
> from LTH, LTI and LTHI and replaces them with either 
> Inner/OuterViewportScrollLayer (dual-layer operation only 
> exists at present if the --enable-pinch-virtual-viewport flag 
> is specified, otherwise behavior is unchanged).
> 
> Logic is added to (i) combine scroll offsets for the two 
> viewports before passing it to the embedder, and (ii) 
> splitting any offsets received from the embedder 
> appropriately between the two viewports.
> 
> This CL relies on https://codereview.chromium.org/138453004/ 
> for changes in Blink to support it.
> 
> BUG=148816
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=246812

TBR=enne@chromium.org,aelias@chromium.org,joi@chromium.org,sky@chromium.org,piman@chromium.org,tony@chromium.org,wjmaclean@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=148816

Review URL: https://codereview.chromium.org/146713002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246842 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 4 insertions, 49 deletions

diff --git a/cc/layers/scrollbar_layer_impl_base.cc b/cc/layers/scrollbar_layer_impl_base.cc
index 22583a1..55f46f5 100644
--- a/cc/layers/scrollbar_layer_impl_base.cc
+++ b/cc/layers/scrollbar_layer_impl_base.cc
@@ -5,7 +5,7 @@
 #include "cc/layers/scrollbar_layer_impl_base.h"
 
 #include <algorithm>
-#include "cc/trees/layer_tree_impl.h"
+#include "cc/layers/layer.h"
 #include "ui/gfx/rect_conversions.h"
 
 namespace cc {
@@ -14,12 +14,10 @@ ScrollbarLayerImplBase::ScrollbarLayerImplBase(
     LayerTreeImpl* tree_impl,
     int id,
     ScrollbarOrientation orientation,
-    bool is_left_side_vertical_scrollbar,
-    bool is_overlay)
+    bool is_left_side_vertical_scrollbar)
     : LayerImpl(tree_impl, id),
-      scroll_layer_(NULL),
-      clip_layer_(NULL),
-      is_overlay_scrollbar_(is_overlay),
+      scroll_layer_id_(Layer::INVALID_ID),
+      is_overlay_scrollbar_(false),
       thumb_thickness_scale_factor_(1.f),
       current_pos_(0.f),
       maximum_(0),
@@ -28,50 +26,14 @@ ScrollbarLayerImplBase::ScrollbarLayerImplBase(
       vertical_adjust_(0.f),
       visible_to_total_length_ratio_(1.f) {}
 
-ScrollbarLayerImplBase::~ScrollbarLayerImplBase() {
-}
-
 void ScrollbarLayerImplBase::PushPropertiesTo(LayerImpl* layer) {
   LayerImpl::PushPropertiesTo(layer);
-  DCHECK(layer->ToScrollbarLayer());
-  layer->ToScrollbarLayer()->set_is_overlay_scrollbar(is_overlay_scrollbar_);
-  PushScrollClipPropertiesTo(layer);
-}
-
-void ScrollbarLayerImplBase::PushScrollClipPropertiesTo(LayerImpl* layer) {
-  DCHECK(layer->ToScrollbarLayer());
-  layer->ToScrollbarLayer()->SetScrollLayerById(ScrollLayerId());
-  layer->ToScrollbarLayer()->SetClipLayerById(ClipLayerId());
 }
 
 ScrollbarLayerImplBase* ScrollbarLayerImplBase::ToScrollbarLayer() {
   return this;
 }
 
-void ScrollbarLayerImplBase::SetScrollLayerById(int id) {
-  LayerImpl* scroll_layer = layer_tree_impl()->LayerById(id);
-  if (scroll_layer_ == scroll_layer)
-    return;
-
-  if (scroll_layer_)
-    scroll_layer_->RemoveScrollbar(this);
-  scroll_layer_ = scroll_layer;
-  if (scroll_layer_)
-    scroll_layer_->AddScrollbar(this);
-}
-
-void ScrollbarLayerImplBase::SetClipLayerById(int id) {
-  LayerImpl* clip_layer = layer_tree_impl()->LayerById(id);
-  if (clip_layer_ == clip_layer)
-    return;
-
-  if (clip_layer_)
-    clip_layer_->RemoveScrollbar(this);
-  clip_layer_ = clip_layer;
-  if (clip_layer_)
-    clip_layer_->AddScrollbar(this);
-}
-
 gfx::Rect ScrollbarLayerImplBase::ScrollbarLayerRectToContentRect(
     const gfx::RectF& layer_rect) const {
   // Don't intersect with the bounds as in LayerRectToContentRect() because
@@ -215,11 +177,4 @@ gfx::Rect ScrollbarLayerImplBase::ComputeThumbQuadRect() const {
   return ScrollbarLayerRectToContentRect(thumb_rect);
 }
 
-void ScrollbarLayerImplBase::ScrollbarParametersDidChange() {
-  if (!clip_layer_ || !scroll_layer_)
-    return;
-
-  scroll_layer_->SetScrollbarPosition(this, clip_layer_);
-}
-
 }  // namespace cc