Allow CanvasSkia to bind to an existing SkCanvas.

ui/gfx/render_text.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/gfx/render_text.h"
 
 #include <algorithm>
 
 #include "base/i18n/break_iterator.h"
 #include "base/logging.h"
@@ skipping 334 matching lines @@
     bounds.set_width(font.GetStringWidth(text));
     canvas->DrawStringInt(text, font, i->foreground, bounds);
 
     // Draw the strikethrough.
     if (i->strike) {
       SkPaint paint;
       paint.setAntiAlias(true);
       paint.setStyle(SkPaint::kFill_Style);
       paint.setColor(i->foreground);
       paint.setStrokeWidth(kStrikeWidth);
-      canvas->AsCanvasSkia()->drawLine(SkIntToScalar(bounds.x()),
-                                       SkIntToScalar(bounds.bottom()),
-                                       SkIntToScalar(bounds.right()),
-                                       SkIntToScalar(bounds.y()),
-                                       paint);
+      canvas->GetSkCanvas()->drawLine(SkIntToScalar(bounds.x()),
+                                      SkIntToScalar(bounds.bottom()),
+                                      SkIntToScalar(bounds.right()),
+                                      SkIntToScalar(bounds.y()),
+                                      paint);
     }
 
     bounds.set_x(bounds.x() + bounds.width());
   }
 
   // Paint cursor. Replace cursor is drawn as rectangle for now.
   Rect cursor(GetUpdatedCursorBounds());
   if (cursor_visible() && focused())
     canvas->DrawRectInt(kCursorColor, cursor.x(), cursor.y(),
                         cursor.width(), cursor.height());
@@ skipping 260 matching lines @@
     // LTR character.
     //
     // Pan to show the cursor when it overflows to the left.
     delta_offset = display_rect_.x() - cursor_bounds_.x();
   }
   display_offset_.Offset(delta_offset, 0);
   cursor_bounds_.Offset(delta_offset, 0);
 }
 
 }  // namespace gfx