Fix a FORWARD_NULL defect reported by Coverity.

ui/views/controls/scroll_view.cc

 // Copyright (c) 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 "ui/views/controls/scroll_view.h"
 
 #include "base/logging.h"
 #include "ui/views/controls/scrollbar/native_scroll_bar.h"
 #include "ui/views/widget/root_view.h"
 
@@ skipping 244 matching lines @@
     // This is no op if bounds are the same
     contents_->SetBounds(-x, -y, contents_->width(), contents_->height());
   }
 }
 
 gfx::Rect ScrollView::GetVisibleRect() const {
   if (!contents_)
     return gfx::Rect();
 
   const int x =
-      (horiz_sb_ && horiz_sb_->IsVisible()) ? horiz_sb_->GetPosition() : 0;
+      horiz_sb_->IsVisible() ? horiz_sb_->GetPosition() : 0;
   const int y =
-      (vert_sb_ && vert_sb_->IsVisible()) ? vert_sb_->GetPosition() : 0;
+      vert_sb_->IsVisible() ? vert_sb_->GetPosition() : 0;
   return gfx::Rect(x, y, viewport_->width(), viewport_->height());
 }
 
 void ScrollView::ScrollContentsRegionToBeVisible(const gfx::Rect& rect) {
-  if (!contents_ || ((!horiz_sb_ || !horiz_sb_->IsVisible()) &&
-                     (!vert_sb_ || !vert_sb_->IsVisible()))) {
+  if (!contents_ || (!horiz_sb_->IsVisible() && !vert_sb_->IsVisible()))
     return;
-  }
 
   // Figure out the maximums for this scroll view.
   const int contents_max_x =
       std::max(viewport_->width(), contents_->width());
   const int contents_max_y =
       std::max(viewport_->height(), contents_->height());
 
   // Make sure x and y are within the bounds of [0,contents_max_*].
   int x = std::max(0, std::min(contents_max_x, rect.x()));
   int y = std::max(0, std::min(contents_max_y, rect.y()));
@@ skipping 206 matching lines @@
 
 VariableRowHeightScrollHelper::RowInfo
     FixedRowHeightScrollHelper::GetRowInfo(int y) {
   if (y < top_margin_)
     return RowInfo(0, top_margin_);
   return RowInfo((y - top_margin_) / row_height_ * row_height_ + top_margin_,
                  row_height_);
 }
 
 }  // namespace views