Remove unused gfx::Canvas API

ui/gfx/canvas.cc

 // Copyright (c) 2012 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/canvas.h"
 
 #include <cmath>
 #include <limits>
 
 #include "base/i18n/rtl.h"
@@ skipping 513 matching lines @@
   paint.setShader(shader.get());
   paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
 
   SkRect dest_rect = { SkIntToScalar(dest_x),
                        SkIntToScalar(dest_y),
                        SkIntToScalar(dest_x + w),
                        SkIntToScalar(dest_y + h) };
   canvas_->drawRect(dest_rect, paint);
 }
 
-NativeDrawingContext Canvas::BeginPlatformPaint() {
-  return skia::BeginPlatformPaint(canvas_);
-}
-
-void Canvas::EndPlatformPaint() {
-  skia::EndPlatformPaint(canvas_);
-}
-
 void Canvas::Transform(const gfx::Transform& transform) {
   canvas_->concat(transform.matrix());
 }
 
 bool Canvas::IntersectsClipRectInt(int x, int y, int w, int h) {
   SkRect clip;
   return canvas_->getClipBounds(&clip) &&
       clip.intersect(SkIntToScalar(x), SkIntToScalar(y), SkIntToScalar(x + w),
                      SkIntToScalar(y + h));
 }
@@ skipping 69 matching lines @@
   // by the paint).
   SkPaint p(paint);
   p.setFilterQuality(filter ? kLow_SkFilterQuality : kNone_SkFilterQuality);
   p.setShader(shader.get());
 
   // The rect will be filled by the bitmap.
   canvas_->drawRect(dest_rect, p);
 }
 
 }  // namespace gfx