cc: Add checker-imaging support to TileManager.

cc/tiles/checker_image_tracker_unittest.cc

+// Copyright 2017 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/tiles/checker_image_tracker.h"
+
+#include "base/bind.h"
+#include "base/memory/ptr_util.h"
+#include "base/run_loop.h"
+#include "base/threading/thread_task_runner_handle.h"
+#include "cc/test/skia_common.h"
+#include "cc/tiles/image_controller.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+class TestImageController : public ImageController {
+ public:
+  TestImageController()
+      : ImageController(base::ThreadTaskRunnerHandle::Get().get(),
+                        base::ThreadTaskRunnerHandle::Get()) {}

[vmpstr, 2017/02/13 22:49:31]

Hmm on shutdown I thought one of the threads waits on the other? Wouldn't that
deadlock? Or is that behavior overridden here? If so, can you add a comment to
make it clear?

[Khushal, 2017/02/14 05:10:22]

It doesn't go to stop the worker because we never set the cache, which is not
necessary because we override the calls necessary here.

May be we should pull out this functionality into a separate interface to use
here and DecodedImageTracker?

+
+  ~TestImageController() override { DCHECK_EQ(locked_images_.size(), 0U); }
+
+  int num_of_locked_images() const { return locked_images_.size(); }
+
+  void UnlockImageDecode(ImageDecodeRequestId id) override {
+    DCHECK_EQ(locked_images_.count(id), 1U);
+    locked_images_.erase(id);
+  }
+
+  ImageDecodeRequestId QueueImageDecode(
+      sk_sp<const SkImage> image,
+      const ImageDecodedCallback& callback) override {
+    ImageDecodeRequestId request_id = next_image_request_id_++;
+    locked_images_.insert(request_id);
+
+    // Post the callback asynchronously to match the behaviour in
+    // ImageController.
+    base::ThreadTaskRunnerHandle::Get()->PostTask(

[vmpstr, 2017/02/13 22:49:31]

You can use the underlying worker here, just make the private block protected
for testing purposes.

[Khushal, 2017/02/14 05:10:23]

Done.

+        FROM_HERE, base::Bind(callback, request_id));
+
+    return request_id;
+  }
+
+ private:
+  ImageDecodeRequestId next_image_request_id_ = 1U;
+  std::unordered_set<ImageDecodeRequestId> locked_images_;
+};
+
+class CheckerImageTrackerTest : public testing::Test,
+                                public CheckerImageTrackerClient {
+ public:
+  void SetUpTracker(bool enabled) {

[vmpstr, 2017/02/13 22:49:31]

rename the variable to something better like "checker_images_enabled"; write
TearDown as well to reset the tracker

[Khushal, 2017/02/14 05:10:22]

Done.

+    checker_image_tracker_ = base::MakeUnique<CheckerImageTracker>(
+        &image_controller_, this, enabled);
+  }
+
+  DrawImage CreateImage(bool checkerable) {
+    int width = checkerable ? 512 : 16;

[vmpstr, 2017/02/13 22:49:31]

Make the constants kConstants at the top; s/width/dimension/

[Khushal, 2017/02/14 05:10:23]

Done.

+    sk_sp<SkImage> image = CreateDiscardableImage(gfx::Size(width, width));
+    return DrawImage(image, SkIRect::MakeWH(image->width(), image->height()),
+                     kNone_SkFilterQuality, SkMatrix::I());
+  }
+
+  // CheckerImageTrackerClient implementation.
+  void NeedsInvalidationForCheckerImagedTiles() override {
+    invalidation_request_pending_ = true;
+  }
+
+ protected:
+  TestImageController image_controller_;
+  std::unique_ptr<CheckerImageTracker> checker_image_tracker_;
+
+  bool invalidation_request_pending_ = false;
+};
+
+TEST_F(CheckerImageTrackerTest, Disabled) {

[vmpstr, 2017/02/13 22:49:31]

s/Disabled/CheckerImagesDisabled/

[Khushal, 2017/02/14 05:10:22]

Done.

+  // Ensures that the tracker doesn't filter any images for checkering if it is
+  // disabled.
+  SetUpTracker(false);
+
+  std::vector<DrawImage> draw_images;
+  ImageIdFlatSet checkered_images;
+  draw_images.push_back(CreateImage(true));
+  checker_image_tracker_->FilterImagesForCheckeringForTile(
+      &draw_images, &checkered_images, WhichTree::PENDING_TREE);
+  EXPECT_EQ(draw_images.size(), 1U);
+  EXPECT_EQ(checkered_images.size(), 0U);
+  EXPECT_EQ(image_controller_.num_of_locked_images(), 0);
+}
+
+TEST_F(CheckerImageTrackerTest, UpdatesImagesAtomically) {
+  // Ensures that the tracker updates images atomically for each frame.
+  SetUpTracker(true);
+
+  DrawImage checkerable_image = CreateImage(true);

[vmpstr, 2017/02/13 22:49:31]

instead of true/false, maybe make an enum with two values to make it clear what
these mean

[Khushal, 2017/02/14 05:10:23]

Done.

+  DrawImage non_checkerable_image = CreateImage(false);
+  ImageIdFlatSet checkered_images;
+  std::vector<DrawImage> draw_images;
+
+  // First request to filter images.
+  draw_images.clear();

[vmpstr, 2017/02/13 22:49:31]

don't need to clear if you just create it :)

[Khushal, 2017/02/14 05:10:23]

I just copied this block everywhere. :P
Done.

+  draw_images.push_back(checkerable_image);
+  draw_images.push_back(non_checkerable_image);
+  draw_images.push_back(checkerable_image);
+  checkered_images.clear();

[vmpstr, 2017/02/13 22:49:31]

same here

[Khushal, 2017/02/14 05:10:22]

Done.

+  checker_image_tracker_->FilterImagesForCheckeringForTile(
+      &draw_images, &checkered_images, WhichTree::PENDING_TREE);
+
+  EXPECT_EQ(draw_images.size(), 1U);
+  EXPECT_EQ(draw_images[0].image(), non_checkerable_image.image());
+  EXPECT_EQ(checkered_images.size(), 1U);
+  EXPECT_EQ(checkered_images.count(checkerable_image.image()->uniqueID()), 1U);
+  EXPECT_EQ(image_controller_.num_of_locked_images(), 1);
+
+  // Run pending task to indicate completion of decode request to the tracker.
+  // This should send an impl-side invalidation request to the client. The
+  // images must remain locked until the sync tree to which the invalidations
+  // are added is activated.
+  base::RunLoop().RunUntilIdle();
+  EXPECT_TRUE(invalidation_request_pending_);
+  EXPECT_EQ(image_controller_.num_of_locked_images(), 1);
+
+  // Continue checkering the image until the set of images to invalidate is
+  // pulled.
+  draw_images.clear();
+  draw_images.push_back(checkerable_image);
+  checkered_images.clear();
+  checker_image_tracker_->FilterImagesForCheckeringForTile(
+      &draw_images, &checkered_images, WhichTree::PENDING_TREE);
+  EXPECT_EQ(draw_images.size(), 0U);
+  EXPECT_EQ(checkered_images.size(), 1U);
+  EXPECT_EQ(image_controller_.num_of_locked_images(), 1);
+
+  std::unordered_set<ImageId> invalidated_images =
+      checker_image_tracker_->TakeImagesToInvalidateOnSyncTree();
+
+  // Use the same set of draw images to ensure that they are not checkered on
+  // the pending tree now.
+  draw_images.clear();
+  draw_images.push_back(checkerable_image);
+  draw_images.push_back(non_checkerable_image);
+  checkered_images.clear();
+  checker_image_tracker_->FilterImagesForCheckeringForTile(
+      &draw_images, &checkered_images, WhichTree::PENDING_TREE);
+  EXPECT_EQ(draw_images.size(), 2U);
+  EXPECT_EQ(checkered_images.size(), 0U);
+
+  // Use this set to make the same request from the active tree, we should
+  // continue checkering this image on the active tree until activation.
+  draw_images.clear();
+  draw_images.push_back(checkerable_image);
+  draw_images.push_back(non_checkerable_image);
+  checkered_images.clear();
+  checker_image_tracker_->FilterImagesForCheckeringForTile(
+      &draw_images, &checkered_images, WhichTree::ACTIVE_TREE);
+  EXPECT_EQ(draw_images.size(), 1U);
+  EXPECT_EQ(draw_images[0].image(), non_checkerable_image.image());
+  EXPECT_EQ(checkered_images.size(), 1U);
+  EXPECT_EQ(checkered_images.count(checkerable_image.image()->uniqueID()), 1U);
+
+  // Activate the sync tree. The images should be unlocked upon activation.
+  EXPECT_EQ(image_controller_.num_of_locked_images(), 1);
+  checker_image_tracker_->DidActivateSyncTree();
+}
+
+TEST_F(CheckerImageTrackerTest, NoConsecutiveCheckeringForImage) {
+  // Ensures that if an image is decoded and invalidated once, it is not
+  // checkered again in subsequent frames.
+  SetUpTracker(true);
+
+  DrawImage checkerable_image = CreateImage(true);
+  DrawImage non_checkerable_image = CreateImage(false);
+  ImageIdFlatSet checkered_images;
+  std::vector<DrawImage> draw_images;
+
+  draw_images.clear();
+  draw_images.push_back(checkerable_image);
+  checkered_images.clear();
+  checker_image_tracker_->FilterImagesForCheckeringForTile(
+      &draw_images, &checkered_images, WhichTree::PENDING_TREE);
+  EXPECT_EQ(draw_images.size(), 0U);
+  EXPECT_EQ(checkered_images.size(), 1U);
+
+  // Trigger decode completion, take images to invalidate and activate the sync
+  // tree.
+  base::RunLoop().RunUntilIdle();
+  checker_image_tracker_->TakeImagesToInvalidateOnSyncTree();
+  checker_image_tracker_->DidActivateSyncTree();
+
+  // Subsequent requests for this image should not be checkered.
+  draw_images.clear();
+  draw_images.push_back(checkerable_image);
+  checkered_images.clear();
+  checker_image_tracker_->FilterImagesForCheckeringForTile(
+      &draw_images, &checkered_images, WhichTree::PENDING_TREE);
+  EXPECT_EQ(draw_images.size(), 1U);
+  EXPECT_EQ(checkered_images.size(), 0U);
+}
+
+}  // namespace

[vmpstr, 2017/02/13 22:49:31]

I think we might need a few more tests, like things on active and pending which
gets checkerboarded and when

[Khushal, 2017/02/14 05:10:22]

I added one more test for checkering on pending and active tree and all that
state tracking. Anything else I'm missing?

+}  // namespace cc