ui: Introduce CanvasPainter, remove PaintContext(gfx::Canvas*).

ui/views/cocoa/bridged_content_view.mm

 // Copyright 2014 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.
 
 #import "ui/views/cocoa/bridged_content_view.h"
 
 #include "base/logging.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "ui/base/ime/text_input_client.h"
-#include "ui/compositor/paint_context.h"
+#include "ui/compositor/canvas_painter.h"
 #import "ui/events/cocoa/cocoa_event_utils.h"
 #include "ui/events/keycodes/dom/dom_code.h"
 #import "ui/events/keycodes/keyboard_code_conversion_mac.h"
 #include "ui/gfx/canvas_paint_mac.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/strings/grit/ui_strings.h"
 #include "ui/views/controls/menu/menu_controller.h"
 #include "ui/views/ime/input_method.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
@@ skipping 283 matching lines @@
   // Note that BridgedNativeWidget uses -[NSWindow setAutodisplay:NO] to
   // suppress calls to this when the window is known to be hidden.
   if (!hostedView_)
     return;
 
   // If there's a layer, painting occurs in BridgedNativeWidget::OnPaintLayer().
   if (hostedView_->GetWidget()->GetLayer())
     return;
 
   gfx::CanvasSkiaPaint canvas(dirtyRect, false /* opaque */);
-  hostedView_->GetWidget()->OnNativeWidgetPaint(ui::PaintContext(&canvas));
+  hostedView_->GetWidget()->OnNativeWidgetPaint(
+      ui::CanvasPainter(&canvas, 1.f).context());
 }
 
 - (NSTextInputContext*)inputContext {
   if (!hostedView_)
     return [super inputContext];
 
   // If a menu is active, and -[NSView interpretKeyEvents:] asks for the
   // input context, return nil. This ensures the action message is sent to
   // the view, rather than any NSTextInputClient a subview has installed.
   MenuController* menuController = MenuController::GetActiveInstance();
@@ skipping 379 matching lines @@
   }
 
   return [super accessibilityAttributeValue:attribute];
 }
 
 - (id)accessibilityHitTest:(NSPoint)point {
   return [hostedView_->GetNativeViewAccessible() accessibilityHitTest:point];
 }
 
 @end