Revert "[Impeller] remove image upload workarounds. (#47209)"

This reverts commit 8eb5909.

Author: Jonah Williams

lib/ui/painting/image_decoder_impeller.cc

@@ -10,13 +10,14 @@
 #include "flutter/fml/make_copyable.h"
 #include "flutter/fml/trace_event.h"
 #include "flutter/impeller/core/allocator.h"
+#include "flutter/impeller/core/texture.h"
 #include "flutter/impeller/display_list/dl_image_impeller.h"
 #include "flutter/impeller/renderer/command_buffer.h"
 #include "flutter/impeller/renderer/context.h"
+#include "flutter/lib/ui/painting/image_decoder_skia.h"
 #include "impeller/base/strings.h"
 #include "impeller/display_list/skia_conversions.h"
 #include "impeller/geometry/size.h"
-
 #include "third_party/skia/include/core/SkAlphaType.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkColorSpace.h"
@@ -31,6 +32,42 @@
 
 namespace flutter {
 
+class MallocDeviceBuffer : public impeller::DeviceBuffer {
+ public:
+  explicit MallocDeviceBuffer(impeller::DeviceBufferDescriptor desc)
+      : impeller::DeviceBuffer(desc) {
+    data_ = static_cast<uint8_t*>(malloc(desc.size));
+  }
+
+  ~MallocDeviceBuffer() override { free(data_); }
+
+  bool SetLabel(const std::string& label) override { return true; }
+
+  bool SetLabel(const std::string& label, impeller::Range range) override {
+    return true;
+  }
+
+  uint8_t* OnGetContents() const override { return data_; }
+
+  bool OnCopyHostBuffer(const uint8_t* source,
+                        impeller::Range source_range,
+                        size_t offset) override {
+    memcpy(data_ + offset, source + source_range.offset, source_range.length);
+    return true;
+  }
+
+ private:
+  uint8_t* data_;
+
+  FML_DISALLOW_COPY_AND_ASSIGN(MallocDeviceBuffer);
+};
+
+#ifdef FML_OS_ANDROID
+static constexpr bool kShouldUseMallocDeviceBuffer = true;
+#else
+static constexpr bool kShouldUseMallocDeviceBuffer = false;
+#endif  // FML_OS_ANDROID
+
 namespace {
 /**
  *  Loads the gamut as a set of three points (triangle).
@@ -485,7 +522,8 @@ void ImageDecoderImpeller::Decode(fml::RefPtr<ImageDescriptor> descriptor,
                                                  gpu_disabled_switch]() {
           sk_sp<DlImage> image;
           std::string decode_error;
-          if (context->GetCapabilities()->SupportsBufferToTextureBlits()) {
+          if (!kShouldUseMallocDeviceBuffer &&
+              context->GetCapabilities()->SupportsBufferToTextureBlits()) {
             std::tie(image, decode_error) = UploadTextureToPrivate(
                 context, bitmap_result.device_buffer, bitmap_result.image_info,
                 bitmap_result.sk_bitmap, gpu_disabled_switch);
@@ -529,7 +567,9 @@ bool ImpellerAllocator::allocPixelRef(SkBitmap* bitmap) {
                     (bitmap->width() * bitmap->bytesPerPixel());
 
   std::shared_ptr<impeller::DeviceBuffer> device_buffer =
-      allocator_->CreateBuffer(descriptor);
+      kShouldUseMallocDeviceBuffer
+          ? std::make_shared<MallocDeviceBuffer>(descriptor)
+          : allocator_->CreateBuffer(descriptor);
 
   struct ImpellerPixelRef final : public SkPixelRef {
     ImpellerPixelRef(int w, int h, void* s, size_t r)