gpu/SharedImageFactory: add ForTesting method

This CL adds a method to register a backing factory for testing
to SharedImageFactory, to be used in crrev.com/c/1619832. It is
needed since otherwise the GetFactoryByUsage() method starts
digging into the factory specifics and usually for testing this
is not needed and is cumbersome to mock.

Bug: 984836
Change-Id: I8009d54cb2a9576e10c5c63c803b9c6294b60f3f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1699531
Commit-Queue: Miguel Casas <mcasas@chromium.org>
Reviewed-by: Eric Karl <ericrk@chromium.org>
Reviewed-by: Andres Calderon Jaramillo <andrescj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#678338}

gpu/command_buffer/service/shared_image_factory.cc

@@ -152,7 +152,9 @@ bool SharedImageFactory::CreateSharedImage(const Mailbox& mailbox,
   // TODO(ericrk): Make this generic in the future.
   bool allow_legacy_mailbox = false;
   SharedImageBackingFactory* factory = nullptr;
-  if (!using_vulkan_) {
+  if (backing_factory_for_testing_) {
+    factory = backing_factory_for_testing_;
+  } else if (!using_vulkan_) {
     allow_legacy_mailbox = true;
     factory = gl_backing_factory_.get();
   } else {
@@ -262,6 +264,11 @@ bool SharedImageFactory::OnMemoryDump(
   return true;
 }
 
+void SharedImageFactory::RegisterSharedImageBackingFactoryForTesting(
+    SharedImageBackingFactory* factory) {
+  backing_factory_for_testing_ = factory;
+}
+
 bool SharedImageFactory::IsSharedBetweenThreads(uint32_t usage) {
   // If |shared_image_manager_| is thread safe, it means the display is running
   // on a separate thread (which uses a separate GL context or VkDeviceQueue).
@@ -273,6 +280,9 @@ SharedImageBackingFactory* SharedImageFactory::GetFactoryByUsage(
     uint32_t usage,
     bool* allow_legacy_mailbox,
     gfx::GpuMemoryBufferType gmb_type) {
+  if (backing_factory_for_testing_)
+    return backing_factory_for_testing_;
+
   bool using_dawn = usage & SHARED_IMAGE_USAGE_WEBGPU;
   bool vulkan_usage = using_vulkan_ && (usage & SHARED_IMAGE_USAGE_DISPLAY);
   bool gl_usage = usage & SHARED_IMAGE_USAGE_GLES2;

gpu/command_buffer/service/shared_image_factory.h

@@ -97,6 +97,9 @@ class GPU_GLES2_EXPORT SharedImageFactory {
   bool RegisterBacking(std::unique_ptr<SharedImageBacking> backing,
                        bool allow_legacy_mailbox);
 
+  void RegisterSharedImageBackingFactoryForTesting(
+      SharedImageBackingFactory* factory);
+
  private:
   bool IsSharedBetweenThreads(uint32_t usage);
   SharedImageBackingFactory* GetFactoryByUsage(
@@ -128,6 +131,8 @@ class GPU_GLES2_EXPORT SharedImageFactory {
   // Used for creating DXGI Swap Chain.
   std::unique_ptr<SwapChainFactoryDXGI> swap_chain_factory_;
 #endif  // OS_WIN
+
+  SharedImageBackingFactory* backing_factory_for_testing_ = nullptr;
 };
 
 class GPU_GLES2_EXPORT SharedImageRepresentationFactory {