Make ResourceInterface::Get* const

Sync from missive: crrev.com/c/3681518

Bug: b:214039157
Change-Id: I95d275ae53b40881d74676846a76946829e42c90
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3681626
Commit-Queue: Hong Xu <[email protected]>
Reviewed-by: Leonid Baraz <[email protected]>
Auto-Submit: Hong Xu <[email protected]>
Commit-Queue: Leonid Baraz <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1009402}
diff --git a/components/reporting/resources/resource_interface.h b/components/reporting/resources/resource_interface.h
index 1e0e9e2..235f42f 100644
--- a/components/reporting/resources/resource_interface.h
+++ b/components/reporting/resources/resource_interface.h
@@ -29,10 +29,10 @@
   virtual void Discard(uint64_t size) = 0;
 
   // Returns total amount.
-  virtual uint64_t GetTotal() = 0;
+  virtual uint64_t GetTotal() const = 0;
 
   // Returns current used amount.
-  virtual uint64_t GetUsed() = 0;
+  virtual uint64_t GetUsed() const = 0;
 
   // Test only: Sets non-default usage limit.
   virtual void Test_SetTotal(uint64_t test_total) = 0;