Revert of Add stable id to PaintImage.

cc/paint/discardable_image_map_unittest.cc

 // Copyright 2015 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 "cc/paint/discardable_image_map.h"
 
 #include <stddef.h>
 
 #include <memory>
 
@@ skipping 26 matching lines @@
   sk_sp<const SkImage> image;
   gfx::Rect image_rect;
   SkSize scale;
 };
 
 sk_sp<PaintRecord> CreateRecording(const sk_sp<SkImage>& discardable_image,
                                    const gfx::Rect& visible_rect) {
   PaintRecorder recorder;
   PaintCanvas* canvas =
       recorder.beginRecording(visible_rect.width(), visible_rect.height());
-  canvas->drawImage(PaintImage(PaintImage::GetNextId(), discardable_image,
-                               PaintImage::AnimationType::STATIC,
-                               PaintImage::CompletionState::DONE),
-                    0, 0, nullptr);
+  canvas->drawImage(
+      PaintImage(discardable_image, PaintImage::AnimationType::STATIC,
+                 PaintImage::CompletionState::DONE),
+      0, 0, nullptr);
   sk_sp<PaintRecord> record = recorder.finishRecordingAsPicture();
   return record;
 }
 
 }  // namespace
 
 class DiscardableImageMapTest : public testing::Test {
  public:
   std::vector<PositionScaleDrawImage> GetDiscardableImagesInRect(
       const DiscardableImageMap& image_map,
@@ skipping 610 matching lines @@
   EXPECT_EQ(1u, images.size());
   EXPECT_TRUE(images[0].image == discardable_image);
   EXPECT_EQ(gfx::Rect(250, 250), inset_rects[0]);
 }
 
 TEST_F(DiscardableImageMapTest, GathersDiscardableImagesFromNestedOps) {
   sk_sp<PaintRecord> internal_record = sk_make_sp<PaintRecord>();
   sk_sp<SkImage> discardable_image =
       CreateDiscardableImage(gfx::Size(100, 100));
   internal_record->push<DrawImageOp>(
-      PaintImage(PaintImage::GetNextId(), discardable_image,
-                 PaintImage::AnimationType::STATIC,
+      PaintImage(discardable_image, PaintImage::AnimationType::STATIC,
                  PaintImage::CompletionState::DONE),
       0.f, 0.f, nullptr);
 
   sk_sp<PaintRecord> list_record = sk_make_sp<PaintRecord>();
   sk_sp<SkImage> discardable_image2 =
       CreateDiscardableImage(gfx::Size(100, 100));
   list_record->push<DrawImageOp>(
-      PaintImage(PaintImage::GetNextId(), discardable_image2,
-                 PaintImage::AnimationType::STATIC,
+      PaintImage(discardable_image2, PaintImage::AnimationType::STATIC,
                  PaintImage::CompletionState::DONE),
       100.f, 100.f, nullptr);
   scoped_refptr<DisplayItemList> display_list = new DisplayItemList;
   display_list->CreateAndAppendDrawingItem<DrawingDisplayItem>(
       gfx::Rect(100, 100, 100, 100), list_record);
   display_list->Finalize();
 
   PaintOpBuffer buffer;
   buffer.push<DrawRecordOp>(internal_record);
   buffer.push<DrawDisplayItemListOp>(display_list);
@@ skipping 12 matching lines @@
   EXPECT_TRUE(discardable_image == images[0].image());
 
   images.clear();
   image_map_.GetDiscardableImagesInRect(gfx::Rect(105, 105, 5, 95), 1.f,
                                         target_color_space, &images);
   EXPECT_EQ(1u, images.size());
   EXPECT_TRUE(discardable_image2 == images[0].image());
 }
 
 }  // namespace cc