This patch removes readPixels from PaintCanvas.

Most of the changes replace canvas read pixels call in favor
of first getting the bitmap, and then doing a readpixels on that.

CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2792133002
Cr-Commit-Position: refs/heads/master@{#462984}

ash/common/wallpaper/wallpaper_controller_unittest.cc

@@ -165,18 +165,15 @@ class WallpaperControllerTest : public test::AshTestBase {
     gfx::Canvas canvas(size, device_scale_factor, true);
     view->OnPaint(&canvas);
 
-    int canvas_width = canvas.sk_canvas()->imageInfo().width();
-    int canvas_height = canvas.sk_canvas()->imageInfo().height();
-    SkBitmap bitmap;
-    bitmap.allocN32Pixels(canvas_width, canvas_height);
-    canvas.sk_canvas()->readPixels(&bitmap, 0, 0);
-
-    for (int i = 0; i < canvas_width; i++) {
-      for (int j = 0; j < canvas_height; j++) {
-        if (i >= (canvas_width - image_width) / 2 &&
-            i < (canvas_width + image_width) / 2 &&
-            j >= (canvas_height - image_height) / 2 &&
-            j < (canvas_height + image_height) / 2) {
+    SkBitmap bitmap = canvas.GetBitmap();
+    int bitmap_width = bitmap.width();
+    int bitmap_height = bitmap.height();
+    for (int i = 0; i < bitmap_width; i++) {
+      for (int j = 0; j < bitmap_height; j++) {
+        if (i >= (bitmap_width - image_width) / 2 &&
+            i < (bitmap_width + image_width) / 2 &&
+            j >= (bitmap_height - image_height) / 2 &&
+            j < (bitmap_height + image_height) / 2) {
           EXPECT_EQ(color, bitmap.getColor(i, j));
         } else {
           EXPECT_EQ(SK_ColorBLACK, bitmap.getColor(i, j));

ash/laser/laser_pointer_view.cc

@@ -568,7 +568,7 @@ void LaserPointerView::UpdateBuffer() {
         gfx::ScaleToEnclosingRect(update_rect, scale_factor_);
     uint8_t* data = static_cast<uint8_t*>(gpu_memory_buffer_->memory(0));
     int stride = gpu_memory_buffer_->stride(0);
-    canvas.sk_canvas()->readPixels(
+    canvas.GetBitmap().readPixels(
         SkImageInfo::MakeN32Premul(pixel_rect.width(), pixel_rect.height()),
         data + pixel_rect.y() * stride + pixel_rect.x() * 4, stride, 0, 0);
   }

cc/paint/paint_canvas.h

@@ -34,13 +34,6 @@ class CC_PAINT_EXPORT PaintCanvas {
   virtual void flush() = 0;
 
   virtual SkISize getBaseLayerSize() const = 0;
-  virtual bool readPixels(const SkImageInfo& dest_info,
-                          void* dest_pixels,
-                          size_t dest_row_bytes,
-                          int src_x,
-                          int src_y) = 0;
-  virtual bool readPixels(SkBitmap* bitmap, int src_x, int src_y) = 0;
-  virtual bool readPixels(const SkIRect& srcRect, SkBitmap* bitmap) = 0;
   virtual bool writePixels(const SkImageInfo& info,
                            const void* pixels,
                            size_t row_bytes,

cc/paint/skia_paint_canvas.cc

@@ -42,23 +42,6 @@ SkISize SkiaPaintCanvas::getBaseLayerSize() const {
   return canvas_->getBaseLayerSize();
 }
 
-bool SkiaPaintCanvas::readPixels(const SkImageInfo& dest_info,
-                                 void* dest_pixels,
-                                 size_t dest_row_bytes,
-                                 int src_x,
-                                 int src_y) {
-  return canvas_->readPixels(dest_info, dest_pixels, dest_row_bytes, src_x,
-                             src_y);
-}
-
-bool SkiaPaintCanvas::readPixels(SkBitmap* bitmap, int src_x, int src_y) {
-  return canvas_->readPixels(bitmap, src_x, src_y);
-}
-
-bool SkiaPaintCanvas::readPixels(const SkIRect& srcRect, SkBitmap* bitmap) {
-  return canvas_->readPixels(srcRect, bitmap);
-}
-
 bool SkiaPaintCanvas::writePixels(const SkImageInfo& info,
                                   const void* pixels,
                                   size_t row_bytes,

cc/paint/skia_paint_canvas.h

@@ -39,13 +39,6 @@ class CC_PAINT_EXPORT SkiaPaintCanvas final : public PaintCanvas {
   void flush() override;
 
   SkISize getBaseLayerSize() const override;
-  bool readPixels(const SkImageInfo& dest_info,
-                  void* dest_pixels,
-                  size_t dest_row_bytes,
-                  int src_x,
-                  int src_y) override;
-  bool readPixels(SkBitmap* bitmap, int src_x, int src_y) override;
-  bool readPixels(const SkIRect& srcRect, SkBitmap* bitmap) override;
   bool writePixels(const SkImageInfo& info,
                    const void* pixels,
                    size_t row_bytes,

ui/gfx/canvas.cc

@@ -104,15 +104,14 @@ int Canvas::DefaultCanvasTextAlignment() {
 }
 
 ImageSkiaRep Canvas::ExtractImageRep() const {
-  // Make a bitmap to return, and a canvas to draw into it. We don't just want
-  // to call extractSubset or the copy constructor, since we want an actual copy
-  // of the bitmap.
-  const SkISize size = canvas_->getBaseLayerSize();
-  SkBitmap result;
-  result.allocN32Pixels(size.width(), size.height());
-
-  canvas_->readPixels(&result, 0, 0);
-  return ImageSkiaRep(result, image_scale_);
+  DCHECK(bitmap_);
+  SkBitmap bitmap_copy;
+  // copyTo() will perform a deep copy, which is what we want.
+  bool result = bitmap_->copyTo(&bitmap_copy);
+  // This should succeed since the destination bitmap is empty to begin with.
+  // The only failure is an allocation failure, which we want to DCHECK anyway.
+  DCHECK(result);
+  return ImageSkiaRep(bitmap_copy, image_scale_);
 }
 
 void Canvas::DrawDashedRect(const Rect& rect, SkColor color) {

ui/message_center/views/notification_view_unittest.cc

@@ -132,10 +132,7 @@ class NotificationViewTest : public views::ViewsTestBase,
     canvas.DrawColor(SK_ColorBLACK);
     view->OnPaint(&canvas);
 
-    SkBitmap bitmap;
-    bitmap.allocN32Pixels(canvas_size.width(), canvas_size.height());
-    canvas.sk_canvas()->readPixels(&bitmap, 0, 0);
-
+    SkBitmap bitmap = canvas.GetBitmap();
     // Incrementally inset each edge at its midpoint to find the bounds of the
     // rect containing the image's color. This assumes that the image is
     // centered in the canvas.