Revert of Deletes mojo::Callback

chrome/renderer/chrome_render_thread_observer.cc

Index: chrome/renderer/chrome_render_thread_observer.cc
diff --git a/chrome/renderer/chrome_render_thread_observer.cc b/chrome/renderer/chrome_render_thread_observer.cc
index 60b4190b8b46fb0aa354809e41de65c2e028d8f1..448b7b601dac9913d0a664ffae602bc90ebb3c89 100644
--- a/chrome/renderer/chrome_render_thread_observer.cc
+++ b/chrome/renderer/chrome_render_thread_observer.cc
@@ -170,7 +170,8 @@
     workers_to_go_ = 0;
   }
 
-  void GetUsageData(const GetUsageDataCallback& callback) override {
+  void GetUsageData(const mojo::Callback<void(mojom::ResourceUsageDataPtr)>&
+                        callback) override {
     DCHECK(callback_.is_null());
     weak_factory_.InvalidateWeakPtrs();
     usage_data_ = mojom::ResourceUsageData::New();
@@ -214,7 +215,7 @@
   }
 
   mojom::ResourceUsageDataPtr usage_data_;
-  GetUsageDataCallback callback_;
+  mojo::Callback<void(mojom::ResourceUsageDataPtr)> callback_;
   int workers_to_go_;
   mojo::StrongBinding<mojom::ResourceUsageReporter> binding_;
   base::WeakPtr<ChromeRenderThreadObserver> observer_;