Allow CanvasSkia to bind to an existing SkCanvas.

views/controls/scrollbar/native_scroll_bar_views.cc

Index: views/controls/scrollbar/native_scroll_bar_views.cc
diff --git a/views/controls/scrollbar/native_scroll_bar_views.cc b/views/controls/scrollbar/native_scroll_bar_views.cc
index ac1bc89f4aa771bcda378dee8c1fbdede1b93968..f007b503489abaadf201b39b367851d34235b475 100644
--- a/views/controls/scrollbar/native_scroll_bar_views.cc
+++ b/views/controls/scrollbar/native_scroll_bar_views.cc
@@ -98,7 +98,7 @@ void ScrollBarButton::OnPaint(gfx::Canvas* canvas) {
   gfx::Rect bounds;
   bounds.set_size(GetPreferredSize());
 
-  native_theme->Paint(canvas->AsCanvasSkia(),
+  native_theme->Paint(canvas->GetSkCanvas(),
                       GetNativeThemePart(),
                       GetNativeThemeState(),
                       bounds,
@@ -183,7 +183,7 @@ gfx::Size ScrollBarThumb::GetPreferredSize() {
 void ScrollBarThumb::OnPaint(gfx::Canvas* canvas) {
   const gfx::NativeTheme* native_theme = gfx::NativeTheme::instance();
 
-  native_theme->Paint(canvas->AsCanvasSkia(),
+  native_theme->Paint(canvas->GetSkCanvas(),
                       GetNativeThemePart(),
                       GetNativeThemeState(),
                       GetLocalBounds(),
@@ -302,7 +302,7 @@ void NativeScrollBarViews::OnPaint(gfx::Canvas* canvas) {
   params_.scrollbar_track.track_height = bounds.height();
 
 
-  native_theme->Paint(canvas->AsCanvasSkia(),
+  native_theme->Paint(canvas->GetSkCanvas(),
                       part_,
                       state_,
                       bounds,