Optionally clear PlatformCanvas instances.

ui/gfx/canvas_skia_win.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_skia.h"
 
 #include <limits>
 
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
@@ skipping 532 matching lines @@
                gradient_width, &tail_part, &solid_part);
 
   // Grow |display_rect| by |offset_x|.
   gfx::Rect text_rect(gfx::Point(), display_rect.size());
   if (!is_rtl)
     text_rect.set_x(text_rect.x() - offset_x);
   text_rect.set_width(text_rect.width() + offset_x);
 
   // Create a temporary bitmap to draw the gradient to.
   scoped_ptr<SkCanvas> gradient_canvas(skia::CreateBitmapCanvas(
-      display_rect.width(), display_rect.height(), false));
+      display_rect.width(), display_rect.height(),
+      skia::PlatformDevice::FLAGS_NONE));
 
   {
     skia::ScopedPlatformPaint scoped_platform_paint(canvas_);
     HDC hdc = scoped_platform_paint.GetPlatformSurface();
     if (is_truncating_head)
       DrawTextGradientPart(hdc, gradient_canvas.get(), text, color,
                            font.GetNativeFont(), text_rect, head_part, is_rtl,
                            flags);
     if (is_truncating_tail)
       DrawTextGradientPart(hdc, gradient_canvas.get(), text, color,
                            font.GetNativeFont(), text_rect, tail_part, !is_rtl,
                            flags);
   }
 
   // Draw the solid part.
   canvas_->save(SkCanvas::kClip_SaveFlag);
   ClipRect(solid_part);
   DrawStringInt(text, font, color,
                 text_rect.x(), text_rect.y(),
                 text_rect.width(), text_rect.height(),
                 flags);
   canvas_->restore();
   canvas_->restore();
 }
 
 }  // namespace gfx