chromeos: Use a PaintRecorder to access the Canvas for painting.

Don't use the canvas() from the PaintContext so that we can have the
PaintContext be backed by a DisplayItemList instead in the future.
Access to the Canvas should be done through a PaintRecorder.

R=oshima
BUG=466426

Review URL: https://codereview.chromium.org/1066113002

Cr-Commit-Position: refs/heads/master@{#324115}

chrome/browser/chromeos/display/overscan_calibrator.cc

@@ -12,7 +12,7 @@
 #include "base/callback.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
-#include "ui/compositor/paint_context.h"
+#include "ui/compositor/paint_recorder.h"
 #include "ui/gfx/canvas.h"
 
 namespace chromeos {
@@ -117,18 +117,20 @@ void OverscanCalibrator::UpdateInsets(const gfx::Insets& insets) {
 }
 
 void OverscanCalibrator::OnPaintLayer(const ui::PaintContext& context) {
-  gfx::Canvas* canvas = context.canvas();
+  ui::PaintRecorder recorder(context);
   static const SkColor kTransparent = SkColorSetARGB(0, 0, 0, 0);
   gfx::Rect full_bounds = calibration_layer_->bounds();
   gfx::Rect inner_bounds = full_bounds;
   inner_bounds.Inset(insets_);
-  canvas->FillRect(full_bounds, SK_ColorBLACK);
-  canvas->FillRect(inner_bounds, kTransparent, SkXfermode::kClear_Mode);
+  recorder.canvas()->FillRect(full_bounds, SK_ColorBLACK);
+  recorder.canvas()->FillRect(inner_bounds, kTransparent,
+                              SkXfermode::kClear_Mode);
 
   gfx::Point center = inner_bounds.CenterPoint();
   int vertical_offset = inner_bounds.height() / 2 - kArrowGapWidth;
   int horizontal_offset = inner_bounds.width() / 2 - kArrowGapWidth;
 
+  gfx::Canvas* canvas = recorder.canvas();
   DrawTriangle(center.x(), center.y() + vertical_offset, 0, canvas);
   DrawTriangle(center.x(), center.y() - vertical_offset, 180, canvas);
   DrawTriangle(center.x() - horizontal_offset, center.y(), 90, canvas);

chrome/browser/chromeos/ui/accessibility_focus_ring_layer.cc

@@ -9,7 +9,7 @@
 #include "base/bind.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
-#include "ui/compositor/paint_context.h"
+#include "ui/compositor/paint_recorder.h"
 #include "ui/gfx/canvas.h"
 
 namespace chromeos {
@@ -112,16 +112,15 @@ void AccessibilityFocusRingLayer::Set(const AccessibilityFocusRing& ring) {
 
 void AccessibilityFocusRingLayer::OnPaintLayer(
     const ui::PaintContext& context) {
-  gfx::Vector2d offset = layer()->bounds().OffsetFromOrigin();
+  ui::PaintRecorder recorder(context);
 
   SkPaint paint;
   paint.setFlags(SkPaint::kAntiAlias_Flag);
   paint.setStyle(SkPaint::kStroke_Style);
   paint.setStrokeWidth(2);
 
-  gfx::Canvas* canvas = context.canvas();
-
   SkPath path;
+  gfx::Vector2d offset = layer()->bounds().OffsetFromOrigin();
   const int w = kGradientWidth;
   for (int i = 0; i < w; ++i) {
     paint.setColor(
@@ -129,7 +128,7 @@ void AccessibilityFocusRingLayer::OnPaintLayer(
             255 * (w - i) * (w - i) / (w * w),
             kFocusRingColorRed, kFocusRingColorGreen, kFocusRingColorBlue));
     path = MakePath(ring_, i, offset);
-    canvas->DrawPath(path, paint);
+    recorder.canvas()->DrawPath(path, paint);
   }
 }
 

chrome/browser/chromeos/ui/focus_ring_layer.cc

@@ -7,7 +7,7 @@
 #include "base/bind.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
-#include "ui/compositor/paint_context.h"
+#include "ui/compositor/paint_recorder.h"
 #include "ui/gfx/canvas.h"
 
 namespace chromeos {
@@ -61,20 +61,22 @@ void FocusRingLayer::OnPaintLayer(const ui::PaintContext& context) {
   if (!root_window_ || focus_ring_.IsEmpty())
     return;
 
-  gfx::Canvas* canvas = context.canvas();
-  gfx::Rect bounds = focus_ring_ - layer_->bounds().OffsetFromOrigin();
+  ui::PaintRecorder recorder(context);
+
   SkPaint paint;
   paint.setColor(kShadowColor);
   paint.setFlags(SkPaint::kAntiAlias_Flag);
   paint.setStyle(SkPaint::kStroke_Style);
   paint.setStrokeWidth(2);
+
+  gfx::Rect bounds = focus_ring_ - layer_->bounds().OffsetFromOrigin();
   int r = kShadowRadius;
   for (int i = 0; i < r; i++) {
     // Fade out alpha quadratically.
     paint.setAlpha((kShadowAlpha * (r - i) * (r - i)) / (r * r));
     gfx::Rect outsetRect = bounds;
     outsetRect.Inset(-i, -i, -i, -i);
-    canvas->DrawRect(outsetRect, paint);
+    recorder.canvas()->DrawRect(outsetRect, paint);
   }
 }