Enable -Wdefaulted-function-deleted

The warning still fires when targeting Fuchsia, but the rest should be clean
now.

Bug: 890307
Change-Id: I65db88d025b3d4744f43d5a742fbb4cdb3ae6d40
Reviewed-on: https://chromium-review.googlesource.com/c/1347279Reviewed-by: Primiano Tucci <primiano@chromium.org>
Commit-Queue: Hans Wennborg <hans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610374}

build/config/compiler/BUILD.gn

@@ -1492,10 +1492,13 @@ config("default_warnings") {
           # Ignore warnings about MSVC optimization pragmas.
           # TODO(thakis): Only for no_chromium_code? http://crbug.com/505314
           "-Wno-ignored-pragma-optimize",
-
-          # TODO(hans): https://crbug.com/890307
-          "-Wno-defaulted-function-deleted",
         ]
+        if (is_fuchsia) {
+          cflags += [
+            # TODO(hans): https://crbug.com/890307
+            "-Wno-defaulted-function-deleted",
+          ]
+        }
       }
     }
   }