gpu: Use mojom API for getting video memory usage.

services/ui/gpu/gpu_service.cc

Index: services/ui/gpu/gpu_service.cc
diff --git a/services/ui/gpu/gpu_service.cc b/services/ui/gpu/gpu_service.cc
index 2f10a0711f58defb2c27456f18f95e8fcdf4acf8..c0e224eae456aa9f08042ec1ce96d7f701213a35 100644
--- a/services/ui/gpu/gpu_service.cc
+++ b/services/ui/gpu/gpu_service.cc
@@ -127,6 +127,16 @@ void GpuService::DestroyGpuMemoryBuffer(gfx::GpuMemoryBufferId id,
     gpu_channel_manager_->DestroyGpuMemoryBuffer(id, client_id, sync_token);
 }
 
+void GpuService::GetVideoMemoryUsageStats(
+    const GetVideoMemoryUsageStatsCallback& callback) {
+  gpu::VideoMemoryUsageStats video_memory_usage_stats;
+  if (gpu_channel_manager_) {
+    gpu_channel_manager_->gpu_memory_manager()->GetVideoMemoryUsageStats(
+        &video_memory_usage_stats);
+  }
+  callback.Run(video_memory_usage_stats);
+}
+
 void GpuService::DidCreateOffscreenContext(const GURL& active_url) {
   gpu_host_->DidCreateOffscreenContext(active_url);
 }