Add display-resolution caching to GPU IDC

cc/tiles/gpu_image_decode_controller.cc

Index: cc/tiles/gpu_image_decode_controller.cc
diff --git a/cc/tiles/gpu_image_decode_controller.cc b/cc/tiles/gpu_image_decode_controller.cc
index 8a76daf9cd20278e89c9aed82e6aeb61f9fe6846..ada6a91e081e540ccdeea8d27bfdb13b027aab55 100644
--- a/cc/tiles/gpu_image_decode_controller.cc
+++ b/cc/tiles/gpu_image_decode_controller.cc
@@ -4,6 +4,7 @@
 
 #include "cc/tiles/gpu_image_decode_controller.h"
 
+#include "base/debug/stack_trace.h"
 #include "base/memory/discardable_memory_allocator.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
@@ -14,6 +15,7 @@
 #include "cc/output/context_provider.h"
 #include "cc/raster/tile_task.h"
 #include "cc/resources/resource_format_utils.h"
+#include "cc/tiles/mipmap_util.h"
 #include "gpu/command_buffer/client/context_support.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 #include "gpu_image_decode_controller.h"
@@ -46,16 +48,47 @@ bool SkipImage(const DrawImage& draw_image) {
 }
 
 SkImage::DeferredTextureImageUsageParams ParamsFromDrawImage(
-    const DrawImage& draw_image) {
+    const DrawImage& draw_image,
+    int pre_scale_mip_level) {
   SkImage::DeferredTextureImageUsageParams params;
   params.fMatrix = draw_image.matrix();
   params.fQuality = draw_image.filter_quality();
+  params.fPreScaleMipLevel = pre_scale_mip_level;
 
   return params;
 }
 
+// Calculate the mp level to pre-scale the image to before uploading. We use mip
+// levels rather than exact scales to increase re-use of scaled images.
+int CalculatePreScaleMipLevel(const DrawImage& draw_image) {
+  gfx::Size base_size(draw_image.image()->width(),
+                      draw_image.image()->height());
+  // Ceil our scaled size so that the mip map generated is guaranteed to be
+  // larger.
+  gfx::Size scaled_size = gfx::ScaleToCeiledSize(
+      base_size, draw_image.scale().width(), draw_image.scale().height());
+
+  return MipMapUtil::GetLevelForSize(base_size, scaled_size);
+}
+
+SkSize CalculatePreScaleFactor(const DrawImage& draw_image, int mip_level) {
+  gfx::Size base_size(draw_image.image()->width(),
+                      draw_image.image()->height());
+  return MipMapUtil::GetScaleAdjustmentForLevel(base_size, mip_level);
+}
+
 }  // namespace
 
+GpuImageDecodeController::ImageDataForDrawImageEntry::
+    ImageDataForDrawImageEntry(const scoped_refptr<ImageData>& image_data)
+    : image_data(image_data) {}
+GpuImageDecodeController::ImageDataForDrawImageEntry::
+    ImageDataForDrawImageEntry(const ImageDataForDrawImageEntry&) = default;
+GpuImageDecodeController::ImageDataForDrawImageEntry::
+    ImageDataForDrawImageEntry(ImageDataForDrawImageEntry&&) = default;
+GpuImageDecodeController::ImageDataForDrawImageEntry::
+    ~ImageDataForDrawImageEntry() = default;
+
 // Task which decodes an image and stores the result in discardable memory.
 // This task does not use GPU resources and can be run on any thread.
 class ImageDecodeTaskImpl : public TileTask {
@@ -231,11 +264,26 @@ void GpuImageDecodeController::UploadedImageData::ReportUsageStats() const {
                         usage_stats_.first_ref_wasted);
 }
 
-GpuImageDecodeController::ImageData::ImageData(DecodedDataMode mode,
-                                               size_t size)
-    : mode(mode), size(size) {}
-
-GpuImageDecodeController::ImageData::~ImageData() = default;
+GpuImageDecodeController::ImageData::ImageData(
+    DecodedDataMode mode,
+    size_t size,
+    int pre_scale_mip_level,
+    SkFilterQuality pre_scale_filter_quality)
+    : mode(mode),
+      size(size),
+      pre_scale_mip_level(pre_scale_mip_level),
+      pre_scale_filter_quality(pre_scale_filter_quality) {}
+
+GpuImageDecodeController::ImageData::~ImageData() {
+  // We should never delete ImageData while it is in use or before it has been
+  // cleaned up.
+  DCHECK_EQ(0u, upload.ref_count);
+  DCHECK_EQ(0u, decode.ref_count);
+  DCHECK_EQ(false, decode.is_locked());
+  // This should always be cleaned up before deleting the image, as it needs to
+  // be freed with the GL context lock held.
+  DCHECK(!upload.image());
+}
 
 GpuImageDecodeController::GpuImageDecodeController(ContextProvider* context,
                                                    ResourceFormat decode_format,
@@ -285,10 +333,8 @@ bool GpuImageDecodeController::GetTaskForImageAndRef(
 
   base::AutoLock lock(lock_);
   const auto image_id = draw_image.image()->uniqueID();
-
-  auto found = image_data_.Get(image_id);
-  if (found != image_data_.end()) {
-    ImageData* image_data = found->second.get();
+  ImageData* image_data = GetImageDataForDrawImage(draw_image);
+  if (image_data) {
     if (image_data->is_at_raster) {
       // Image is at-raster, just return, this usage will be at-raster as well.
       *task = nullptr;
@@ -307,32 +353,30 @@ bool GpuImageDecodeController::GetTaskForImageAndRef(
       *task = nullptr;
       return true;
     }
-  }
 
-  // We didn't have a pre-uploaded image, so we need an upload task. Try to find
-  // an existing one.
-  scoped_refptr<TileTask>& existing_task =
-      pending_image_upload_tasks_[image_id];
-  if (existing_task) {
-    // We had an existing upload task, ref the image and return the task.
-    RefImage(draw_image);
-    *task = existing_task;
-    return true;
+    // We didn't have a pre-uploaded image, so we need an upload task. Try to
+    // find an existing one.
+    auto existing_task = pending_image_upload_tasks_.find(
+        GenerateTaskKeyForDrawImage(draw_image));
+    if (existing_task != pending_image_upload_tasks_.end()) {
+      // We had an existing upload task, ref the image and return the task.
+      RefImage(draw_image);
+      *task = existing_task->second;
+      return true;
+    } else {
+    }
   }
 
   // We will be creating a new upload task. If necessary, create a placeholder
   // ImageData to hold the result.
-  std::unique_ptr<ImageData> new_data;
-  ImageData* data;
-  if (found == image_data_.end()) {
+  scoped_refptr<ImageData> new_data;
+  if (!image_data) {
     new_data = CreateImageData(draw_image);
-    data = new_data.get();
-  } else {
-    data = found->second.get();
+    image_data = new_data.get();
   }
 
   // Ensure that the image we're about to decode/upload will fit in memory.
-  if (!EnsureCapacity(data->size)) {
+  if (!EnsureCapacity(image_data->size)) {
     // Image will not fit, do an at-raster decode.
     *task = nullptr;
     return false;
@@ -341,19 +385,20 @@ bool GpuImageDecodeController::GetTaskForImageAndRef(
   // If we had to create new image data, add it to our map now that we know it
   // will fit.
   if (new_data)
-    found = image_data_.Put(image_id, std::move(new_data));
+    image_data_.Put(image_id, std::move(new_data));
 
   // Ref image and create a upload and decode tasks. We will release this ref
   // in UploadTaskCompleted.
   RefImage(draw_image);
-  existing_task = make_scoped_refptr(new ImageUploadTaskImpl(
+  *task = make_scoped_refptr(new ImageUploadTaskImpl(
       this, draw_image, GetImageDecodeTaskAndRef(draw_image, tracing_info),
       tracing_info));
+  pending_image_upload_tasks_.insert(
+      std::make_pair(GenerateTaskKeyForDrawImage(draw_image), *task));
 
   // Ref the image again - this ref is owned by the caller, and it is their
   // responsibility to release it by calling UnrefImage.
   RefImage(draw_image);
-  *task = existing_task;
   return true;
 }
 
@@ -374,16 +419,14 @@ DecodedDrawImage GpuImageDecodeController::GetDecodedImageForDraw(
   TRACE_EVENT0("cc", "GpuImageDecodeController::GetDecodedImageForDraw");
 
   base::AutoLock lock(lock_);
-  const uint32_t unique_id = draw_image.image()->uniqueID();
-  auto found = image_data_.Peek(unique_id);
-  if (found == image_data_.end()) {
+  ImageData* image_data = GetImageDataForDrawImage(draw_image);
+  if (!image_data) {
     // We didn't find the image, create a new entry.
     auto data = CreateImageData(draw_image);
-    found = image_data_.Put(unique_id, std::move(data));
+    image_data = data.get();
+    image_data_.Put(draw_image.image()->uniqueID(), std::move(data));
   }
 
-  ImageData* image_data = found->second.get();
-
   if (!image_data->upload.budgeted) {
     // If image data is not budgeted by this point, it is at-raster.
     image_data->is_at_raster = true;
@@ -406,7 +449,9 @@ DecodedDrawImage GpuImageDecodeController::GetDecodedImageForDraw(
   image_data->upload.mark_used();
   DCHECK(image || image_data->decode.decode_failure);
 
-  DecodedDrawImage decoded_draw_image(std::move(image),
+  SkSize scale_factor =
+      CalculatePreScaleFactor(draw_image, image_data->pre_scale_mip_level);
+  DecodedDrawImage decoded_draw_image(std::move(image), SkSize(), scale_factor,
                                       draw_image.filter_quality());
   decoded_draw_image.set_at_raster_decode(image_data->is_at_raster);
   return decoded_draw_image;
@@ -423,6 +468,7 @@ void GpuImageDecodeController::DrawWithImageFinished(
     return;
 
   base::AutoLock lock(lock_);
+  TRACE_EVENT0("cc", "GpuImageDecodeController::DrawWithImageFinished");
   UnrefImageInternal(draw_image);
 
   // We are mid-draw and holding the context lock, ensure we clean up any
@@ -516,26 +562,26 @@ bool GpuImageDecodeController::OnMemoryDump(
 
 void GpuImageDecodeController::DecodeImage(const DrawImage& draw_image) {
   base::AutoLock lock(lock_);
-  auto found = image_data_.Peek(draw_image.image()->uniqueID());
-  DCHECK(found != image_data_.end());
-  DCHECK(!found->second->is_at_raster);
-  DecodeImageIfNecessary(draw_image, found->second.get());
+  ImageData* image_data = GetImageDataForDrawImage(draw_image);
+  DCHECK(image_data);
+  DCHECK(!image_data->is_at_raster);
+  DecodeImageIfNecessary(draw_image, image_data);
 }
 
 void GpuImageDecodeController::UploadImage(const DrawImage& draw_image) {
   ContextProvider::ScopedContextLock context_lock(context_);
   base::AutoLock lock(lock_);
-  auto found = image_data_.Peek(draw_image.image()->uniqueID());
-  DCHECK(found != image_data_.end());
-  DCHECK(!found->second->is_at_raster);
-  UploadImageIfNecessary(draw_image, found->second.get());
+  ImageData* image_data = GetImageDataForDrawImage(draw_image);
+  DCHECK(image_data);
+  DCHECK(!image_data->is_at_raster);
+  UploadImageIfNecessary(draw_image, image_data);
 }
 
 void GpuImageDecodeController::OnImageDecodeTaskCompleted(
     const DrawImage& draw_image) {
   base::AutoLock lock(lock_);
   // Decode task is complete, remove it from our list of pending tasks.
-  pending_image_decode_tasks_.erase(draw_image.image()->uniqueID());
+  pending_image_decode_tasks_.erase(GenerateTaskKeyForDrawImage(draw_image));
 
   // While the decode task is active, we keep a ref on the decoded data.
   // Release that ref now.
@@ -546,7 +592,7 @@ void GpuImageDecodeController::OnImageUploadTaskCompleted(
     const DrawImage& draw_image) {
   base::AutoLock lock(lock_);
   // Upload task is complete, remove it from our list of pending tasks.
-  pending_image_upload_tasks_.erase(draw_image.image()->uniqueID());
+  pending_image_upload_tasks_.erase(GenerateTaskKeyForDrawImage(draw_image));
 
   // While the upload task is active, we keep a ref on both the image it will be
   // populating, as well as the decode it needs to populate it. Release these
@@ -562,24 +608,22 @@ scoped_refptr<TileTask> GpuImageDecodeController::GetImageDecodeTaskAndRef(
     const TracingInfo& tracing_info) {
   lock_.AssertAcquired();
 
-  const uint32_t image_id = draw_image.image()->uniqueID();
-
   // This ref is kept alive while an upload task may need this decode. We
   // release this ref in UploadTaskCompleted.
   RefImageDecode(draw_image);
 
-  auto found = image_data_.Peek(image_id);
-  if (found != image_data_.end() && found->second->decode.is_locked()) {
+  ImageData* image_data = GetImageDataForDrawImage(draw_image);
+  if (image_data && image_data->decode.is_locked()) {
     // We should never be creating a decode task for an at raster image.
-    DCHECK(!found->second->is_at_raster);
+    DCHECK(!image_data->is_at_raster);
     // We should never be creating a decode for an already-uploaded image.
-    DCHECK(!found->second->upload.image());
+    DCHECK(!image_data->upload.image());
     return nullptr;
   }
 
   // We didn't have an existing locked image, create a task to lock or decode.
   scoped_refptr<TileTask>& existing_task =
-      pending_image_decode_tasks_[image_id];
+      pending_image_decode_tasks_[GenerateTaskKeyForDrawImage(draw_image)];
   if (!existing_task) {
     // Ref image decode and create a decode task. This ref will be released in
     // DecodeTaskCompleted.
@@ -592,38 +636,68 @@ scoped_refptr<TileTask> GpuImageDecodeController::GetImageDecodeTaskAndRef(
 
 void GpuImageDecodeController::RefImageDecode(const DrawImage& draw_image) {
   lock_.AssertAcquired();
-  auto found = image_data_.Peek(draw_image.image()->uniqueID());
-  DCHECK(found != image_data_.end());
-  ++found->second->decode.ref_count;
-  RefCountChanged(found->second.get());
+  auto found =
+      image_data_for_draw_image_.find(GenerateDrawImageKey(draw_image));
+  DCHECK(found != image_data_for_draw_image_.end());
+  ++found->second.ref_count;
+  ++found->second.image_data->decode.ref_count;
+  RefCountChanged(found->second.image_data.get());
 }
 
 void GpuImageDecodeController::UnrefImageDecode(const DrawImage& draw_image) {
   lock_.AssertAcquired();
-  auto found = image_data_.Peek(draw_image.image()->uniqueID());
-  DCHECK(found != image_data_.end());
-  DCHECK_GT(found->second->decode.ref_count, 0u);
-  --found->second->decode.ref_count;
-  RefCountChanged(found->second.get());
+  auto found =
+      image_data_for_draw_image_.find(GenerateDrawImageKey(draw_image));
+  DCHECK(found != image_data_for_draw_image_.end());
+  DCHECK_GT(found->second.image_data->decode.ref_count, 0u);
+  DCHECK_GT(found->second.ref_count, 0u);
+  --found->second.ref_count;
+  --found->second.image_data->decode.ref_count;
+  RefCountChanged(found->second.image_data.get());
+  if (found->second.ref_count == 0u) {
+    image_data_for_draw_image_.erase(found);
+  }
 }
 
 void GpuImageDecodeController::RefImage(const DrawImage& draw_image) {
   lock_.AssertAcquired();
-  auto found = image_data_.Peek(draw_image.image()->uniqueID());
-  DCHECK(found != image_data_.end());
-  ++found->second->upload.ref_count;
-  RefCountChanged(found->second.get());
+  auto found =
+      image_data_for_draw_image_.find(GenerateDrawImageKey(draw_image));
+
+  // If no secondary cache entry was found for the given |draw_image|, then
+  // the draw_image only exists in the primary cache. Create a secondary
+  // cache entry now.
+  if (found == image_data_for_draw_image_.end()) {
+    auto found_image = image_data_.Peek(draw_image.image()->uniqueID());
+    DCHECK(found_image != image_data_.end());
+    DCHECK(found_image->second->pre_scale_mip_level <=
+           CalculatePreScaleMipLevel(draw_image));
+    found = image_data_for_draw_image_
+                .insert(std::make_pair(
+                    GenerateDrawImageKey(draw_image),
+                    ImageDataForDrawImageEntry(found_image->second)))
+                .first;
+  }
+
+  DCHECK(found != image_data_for_draw_image_.end());
+  ++found->second.ref_count;
+  ++found->second.image_data->upload.ref_count;
+  RefCountChanged(found->second.image_data.get());
 }
 
 void GpuImageDecodeController::UnrefImageInternal(const DrawImage& draw_image) {
   lock_.AssertAcquired();
-  auto found = image_data_.Peek(draw_image.image()->uniqueID());
-  DCHECK(found != image_data_.end());
-  DCHECK_GT(found->second->upload.ref_count, 0u);
-  --found->second->upload.ref_count;
-  if (found->second->upload.ref_count == 0)
-    found->second->upload.notify_ref_reached_zero();
-  RefCountChanged(found->second.get());
+  auto found =
+      image_data_for_draw_image_.find(GenerateDrawImageKey(draw_image));
+  DCHECK(found != image_data_for_draw_image_.end());
+  DCHECK_GT(found->second.image_data->upload.ref_count, 0u);
+  DCHECK_GT(found->second.ref_count, 0u);
+  --found->second.ref_count;
+  --found->second.image_data->upload.ref_count;
+  RefCountChanged(found->second.image_data.get());
+  if (found->second.ref_count == 0u) {
+    image_data_for_draw_image_.erase(found);
+  }
 }
 
 // Called any time an image or decode ref count changes. Takes care of any
@@ -634,6 +708,12 @@ void GpuImageDecodeController::RefCountChanged(ImageData* image_data) {
   bool has_any_refs =
       image_data->upload.ref_count > 0 || image_data->decode.ref_count > 0;
 
+  // Don't keep around orphaned images.
+  if (image_data->is_orphaned && !has_any_refs) {
+    images_pending_deletion_.push_back(std::move(image_data->upload.image()));
+    image_data->upload.SetImage(nullptr);
+  }
+
   // Don't keep CPU images if they are unused, these images can be recreated by
   // re-locking discardable (rather than requiring a full upload like GPU
   // images).
@@ -807,10 +887,21 @@ void GpuImageDecodeController::DecodeImageIfNecessary(
         backing_memory =
             base::DiscardableMemoryAllocator::GetInstance()
                 ->AllocateLockedDiscardableMemory(image_data->size);
-        SkImageInfo image_info = CreateImageInfoForDrawImage(draw_image);
-        if (!draw_image.image()->readPixels(image_info, backing_memory->data(),
-                                            image_info.minRowBytes(), 0, 0,
-                                            SkImage::kDisallow_CachingHint)) {
+        DrawImage scaled_draw_image =
+            draw_image.ApplyScale(CalculatePreScaleFactor(
+                draw_image, image_data->pre_scale_mip_level));
+        SkImageInfo scaled_image_info =
+            CreateImageInfoForDrawImage(scaled_draw_image);
+        // We are doing a software scale of the image before handing off to the
+        // GPU.  In order to match GPU scaling quality (which uses mip-maps at
+        // high quality), we want to use at most medium filter quality for the
+        // scale.
+        SkFilterQuality scale_quality =
+            std::max(kMedium_SkFilterQuality, draw_image.filter_quality());
+        SkPixmap full_image_pixmap(scaled_image_info, backing_memory->data(),
+                                   scaled_image_info.minRowBytes());
+        if (!draw_image.image()->scalePixels(full_image_pixmap, scale_quality,
+                                             SkImage::kDisallow_CachingHint)) {
           backing_memory.reset();
         }
         break;
@@ -819,7 +910,8 @@ void GpuImageDecodeController::DecodeImageIfNecessary(
         backing_memory =
             base::DiscardableMemoryAllocator::GetInstance()
                 ->AllocateLockedDiscardableMemory(image_data->size);
-        auto params = ParamsFromDrawImage(draw_image);
+        auto params =
+            ParamsFromDrawImage(draw_image, image_data->pre_scale_mip_level);
         if (!draw_image.image()->getDeferredTextureImageData(
                 *context_threadsafe_proxy_.get(), &params, 1,
                 backing_memory->data())) {
@@ -875,9 +967,13 @@ void GpuImageDecodeController::UploadImageIfNecessary(
     base::AutoUnlock unlock(lock_);
     switch (image_data->mode) {
       case DecodedDataMode::CPU: {
-        SkImageInfo image_info = CreateImageInfoForDrawImage(draw_image);
-        SkPixmap pixmap(image_info, image_data->decode.data()->data(),
-                        image_info.minRowBytes());
+        DrawImage scaled_draw_image =
+            draw_image.ApplyScale(CalculatePreScaleFactor(
+                draw_image, image_data->pre_scale_mip_level));
+        SkImageInfo scaled_image_info =
+            CreateImageInfoForDrawImage(scaled_draw_image);
+        SkPixmap pixmap(scaled_image_info, image_data->decode.data()->data(),
+                        scaled_image_info.minRowBytes());
         uploaded_image =
             SkImage::MakeFromRaster(pixmap, [](const void*, void*) {}, nullptr);
         break;
@@ -899,26 +995,31 @@ void GpuImageDecodeController::UploadImageIfNecessary(
     image_data->upload.SetImage(std::move(uploaded_image));
 }
 
-std::unique_ptr<GpuImageDecodeController::ImageData>
+scoped_refptr<GpuImageDecodeController::ImageData>
 GpuImageDecodeController::CreateImageData(const DrawImage& draw_image) {
   lock_.AssertAcquired();
 
   DecodedDataMode mode;
-  SkImageInfo info = CreateImageInfoForDrawImage(draw_image);
+  int pre_scale_mip_level = CalculatePreScaleMipLevel(draw_image);
   SkImage::DeferredTextureImageUsageParams params =
-      ParamsFromDrawImage(draw_image);
+      ParamsFromDrawImage(draw_image, pre_scale_mip_level);
   size_t data_size = draw_image.image()->getDeferredTextureImageData(
       *context_threadsafe_proxy_.get(), &params, 1, nullptr);
 
   if (data_size == 0) {
     // Can't upload image, too large or other failure. Try to use SW fallback.
-    data_size = info.getSafeSize(info.minRowBytes());
+    DrawImage scaled_draw_image = draw_image.ApplyScale(
+        CalculatePreScaleFactor(draw_image, pre_scale_mip_level));
+    SkImageInfo scaled_image_info =
+        CreateImageInfoForDrawImage(scaled_draw_image);
+    data_size = scaled_image_info.getSafeSize(scaled_image_info.minRowBytes());
     mode = DecodedDataMode::CPU;
   } else {
     mode = DecodedDataMode::GPU;
   }
 
-  return base::WrapUnique(new ImageData(mode, data_size));
+  return make_scoped_refptr(new ImageData(mode, data_size, pre_scale_mip_level,
+                                          draw_image.filter_quality()));
 }
 
 void GpuImageDecodeController::DeletePendingImages() {
@@ -930,10 +1031,81 @@ void GpuImageDecodeController::DeletePendingImages() {
 SkImageInfo GpuImageDecodeController::CreateImageInfoForDrawImage(
     const DrawImage& draw_image) const {
   return SkImageInfo::Make(
-      draw_image.image()->width(), draw_image.image()->height(),
+      draw_image.image()->width() * draw_image.scale().width(),
+      draw_image.image()->height() * draw_image.scale().height(),
       ResourceFormatToClosestSkColorType(format_), kPremul_SkAlphaType);
 }
 
+GpuImageDecodeController::ImageData*
+GpuImageDecodeController::GetImageDataForDrawImage(
+    const DrawImage& draw_image) {
+  lock_.AssertAcquired();
+  {
+    auto found =
+        image_data_for_draw_image_.find(GenerateDrawImageKey(draw_image));
+    if (found != image_data_for_draw_image_.end()) {
+      return found->second.image_data.get();
+    }
+  }
+  {
+    auto found = image_data_.Get(draw_image.image()->uniqueID());
+    if (found != image_data_.end()) {
+      if (IsCompatibleWithDrawImage(found->second.get(), draw_image)) {
+        return found->second.get();
+      } else {
+        found->second->is_orphaned = true;
+        // Call RefCountChanged before erasing the orphaned task to ensure
+        // that we clean up any SkImage safely.
+        RefCountChanged(found->second.get());
+        image_data_.Erase(found);
+      }
+    }
+  }
+
+  return nullptr;
+}
+
+bool GpuImageDecodeController::IsCompatibleWithDrawImage(
+    const ImageData* image_data,
+    const DrawImage& draw_image) const {
+  bool not_scaled = image_data->pre_scale_mip_level == 0;
+  bool scale_is_compatible =
+      CalculatePreScaleMipLevel(draw_image) >=
+          image_data->pre_scale_mip_level &&
+      draw_image.filter_quality() <= image_data->pre_scale_filter_quality;
+  return not_scaled || scale_is_compatible;
+}
+
+GpuImageDecodeController::DrawImageKey
+GpuImageDecodeController::GenerateDrawImageKey(
+    const DrawImage& draw_image) const {
+  DrawImageKey key;
+  key.image_id = draw_image.image()->uniqueID();
+  key.mip_level = CalculatePreScaleMipLevel(draw_image);
+  key.quality = draw_image.filter_quality();
+  return key;
+}
+
+GpuImageDecodeController::DrawImageKey
+GpuImageDecodeController::GenerateTaskKeyForDrawImage(
+    const DrawImage& draw_image) {
+  lock_.AssertAcquired();
+  ImageData* image_data = GetImageDataForDrawImage(draw_image);
+  DDCHECK(image_data);
+  DrawImageKey key;
+  key.image_id = draw_image.image()->uniqueID();
+  key.mip_level = image_data->pre_scale_mip_level;
+  key.quality = image_data->pre_scale_filter_quality;
+  return key;
+}
+
+size_t GpuImageDecodeController::GetDrawImageSizeForTesting(
+    const DrawImage& image) {
+  base::AutoLock lock(lock_);
+  scoped_refptr<ImageData> data = CreateImageData(image);
+  return data->size;
+}
+
 void GpuImageDecodeController::SetImageDecodingFailedForTesting(
     const DrawImage& image) {
   base::AutoLock lock(lock_);