exo: Directly create GpuMemoryBufferImpl when a handle is available.

content/browser/gpu/browser_gpu_memory_buffer_manager.cc

Index: content/browser/gpu/browser_gpu_memory_buffer_manager.cc
diff --git a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
index 5b9d77daf8ee2fe0f5c7fdd5da0f036a556fcebb..f700c1f9276cdbb8a6b709a5c9748b6af66e6834 100644
--- a/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
+++ b/content/browser/gpu/browser_gpu_memory_buffer_manager.cc
@@ -78,23 +78,6 @@ struct BrowserGpuMemoryBufferManager::CreateGpuMemoryBufferRequest {
   std::unique_ptr<gfx::GpuMemoryBuffer> result;
 };
 
-struct BrowserGpuMemoryBufferManager::CreateGpuMemoryBufferFromHandleRequest
-    : public CreateGpuMemoryBufferRequest {
-  CreateGpuMemoryBufferFromHandleRequest(
-      const gfx::GpuMemoryBufferHandle& handle,
-      const gfx::Size& size,
-      gfx::BufferFormat format,
-      int client_id)
-      : CreateGpuMemoryBufferRequest(size,
-                                     format,
-                                     gfx::BufferUsage::GPU_READ,
-                                     client_id,
-                                     gpu::kNullSurfaceHandle),
-        handle(handle) {}
-  ~CreateGpuMemoryBufferFromHandleRequest() {}
-  gfx::GpuMemoryBufferHandle handle;
-};
-
 BrowserGpuMemoryBufferManager::BrowserGpuMemoryBufferManager(
     int gpu_client_id,
     uint64_t gpu_client_tracing_id)
@@ -154,31 +137,6 @@ BrowserGpuMemoryBufferManager::CreateGpuMemoryBuffer(
   return AllocateGpuMemoryBufferForSurface(size, format, usage, surface_handle);
 }
 
-std::unique_ptr<gfx::GpuMemoryBuffer>
-BrowserGpuMemoryBufferManager::CreateGpuMemoryBufferFromHandle(
-    const gfx::GpuMemoryBufferHandle& handle,
-    const gfx::Size& size,
-    gfx::BufferFormat format) {
-  DCHECK(!BrowserThread::CurrentlyOn(BrowserThread::IO));
-
-  CreateGpuMemoryBufferFromHandleRequest request(handle, size, format,
-                                                 gpu_client_id_);
-  BrowserThread::PostTask(
-      BrowserThread::IO, FROM_HERE,
-      base::Bind(&BrowserGpuMemoryBufferManager::
-                     HandleCreateGpuMemoryBufferFromHandleOnIO,
-                 base::Unretained(this),  // Safe as we wait for result below.
-                 base::Unretained(&request)));
-
-  // We're blocking the UI thread, which is generally undesirable.
-  TRACE_EVENT0(
-      "browser",
-      "BrowserGpuMemoryBufferManager::CreateGpuMemoryBufferFromHandle");
-  base::ThreadRestrictions::ScopedAllowWait allow_wait;
-  request.event.Wait();
-  return std::move(request.result);
-}
-
 void BrowserGpuMemoryBufferManager::AllocateGpuMemoryBufferForChildProcess(
     gfx::GpuMemoryBufferId id,
     const gfx::Size& size,
@@ -378,33 +336,6 @@ void BrowserGpuMemoryBufferManager::HandleCreateGpuMemoryBufferOnIO(
   request->event.Signal();
 }
 
-void BrowserGpuMemoryBufferManager::HandleCreateGpuMemoryBufferFromHandleOnIO(
-    CreateGpuMemoryBufferFromHandleRequest* request) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-
-  gfx::GpuMemoryBufferId new_id = content::GetNextGenericSharedMemoryId();
-
-  BufferMap& buffers = clients_[request->client_id];
-  auto insert_result = buffers.insert(std::make_pair(
-      new_id, BufferInfo(request->size, request->handle.type,
-                         request->format, request->usage, 0)));
-  DCHECK(insert_result.second);
-
-  gfx::GpuMemoryBufferHandle handle = request->handle;
-  handle.id = new_id;
-
-  // Note: Unretained is safe as IO thread is stopped before manager is
-  // destroyed.
-  request->result = gpu::GpuMemoryBufferImpl::CreateFromHandle(
-      handle, request->size, request->format, request->usage,
-      base::Bind(
-          &GpuMemoryBufferDeleted,
-          BrowserThread::GetTaskRunnerForThread(BrowserThread::IO),
-          base::Bind(&BrowserGpuMemoryBufferManager::DestroyGpuMemoryBufferOnIO,
-                     base::Unretained(this), new_id, request->client_id)));
-  request->event.Signal();
-}
-
 void BrowserGpuMemoryBufferManager::HandleGpuMemoryBufferCreatedOnIO(
     CreateGpuMemoryBufferRequest* request,
     const gfx::GpuMemoryBufferHandle& handle) {