Run clang-tidy modernize-use-equals-{delete,default} on //ash

See the bugs and cxx post for justification and details:
https://groups.google.com/a/chromium.org/forum/#!topic/cxx/RkOHzIK6Tq8

This change was done using clang-tidy as described here:
https://chromium.googlesource.com/chromium/src/+/lkcr/docs/clang_tidy.md

In some cases the the tool leaves behind a string of commas where it
replaced a member initializer list
(https://bugs.llvm.org/show_bug.cgi?id=35051). They were cleaned up with:
  git diff --name-only | \
    xargs sed -E -i 's/(^\s*|\)\s*):[ ,]*= default/\1 = default/'

BUG=778959,778957

Change-Id: I782d000d8a330fef0bef697d24611303dc63d059
Reviewed-on: https://chromium-review.googlesource.com/789717
Commit-Queue: Chris Watkins <[email protected]>
Reviewed-by: Dan Erat <[email protected]>
Cr-Commit-Position: refs/heads/master@{#519550}
diff --git a/ash/test/ash_test_suite.cc b/ash/test/ash_test_suite.cc
index 100b1e9..ccf694a7 100644
--- a/ash/test/ash_test_suite.cc
+++ b/ash/test/ash_test_suite.cc
@@ -93,7 +93,7 @@
 
 AshTestSuite::AshTestSuite(int argc, char** argv) : TestSuite(argc, argv) {}
 
-AshTestSuite::~AshTestSuite() {}
+AshTestSuite::~AshTestSuite() = default;
 
 void AshTestSuite::Initialize() {
   base::TestSuite::Initialize();