Add an API to get total size of Drive cache including non-evictable ones.

components/drive/chromeos/fake_file_system.cc

Index: components/drive/chromeos/fake_file_system.cc
diff --git a/components/drive/chromeos/fake_file_system.cc b/components/drive/chromeos/fake_file_system.cc
index 695c15da10e855228cfa5e0bedb5bfa815a94922..f3b7cd68231dd67def43f2584013f0a366f7c108 100644
--- a/components/drive/chromeos/fake_file_system.cc
+++ b/components/drive/chromeos/fake_file_system.cc
@@ -253,8 +253,12 @@ void FakeFileSystem::FreeDiskSpaceIfNeededFor(
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 }
 
+void FakeFileSystem::CalculateCacheSize(const CacheSizeCallback& callback) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+}
+
 void FakeFileSystem::CalculateEvictableCacheSize(
-    const EvictableCacheSizeCallback& callback) {
+    const CacheSizeCallback& callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 }