Nest all namespaces

The compiler supports this now.  We can type less going forward.
No functional changes.

Signed-off-by: Stephan Pleines <pleines.stephan@gmail.com>
Change-Id: I29d6fa4f9aacc0e381f1a7637294db0392466995
diff --git a/aos/containers/error_list_test.cc b/aos/containers/error_list_test.cc
index b819ba5..94eabf9 100644
--- a/aos/containers/error_list_test.cc
+++ b/aos/containers/error_list_test.cc
@@ -4,8 +4,7 @@
 
 #include "aos/json_to_flatbuffer_generated.h"
 
-namespace aos {
-namespace testing {
+namespace aos::testing {
 
 enum class TestEnum : int8_t {
   FOO = 0,
@@ -112,5 +111,4 @@
   EXPECT_EQ(b.size(), 3);
 }
 
-}  // namespace testing
-}  // namespace aos
+}  // namespace aos::testing
diff --git a/aos/containers/inlined_vector_test.cc b/aos/containers/inlined_vector_test.cc
index 7368844..c9f2dd2 100644
--- a/aos/containers/inlined_vector_test.cc
+++ b/aos/containers/inlined_vector_test.cc
@@ -6,8 +6,7 @@
 
 DECLARE_bool(die_on_malloc);
 
-namespace aos {
-namespace testing {
+namespace aos::testing {
 
 // Checks that we don't malloc until/unless we need to increase the size of the
 // vector.
@@ -45,5 +44,4 @@
   zero.push_back(1);
   ASSERT_EQ(1, zero[0]);
 }
-}  // namespace testing
-}  // namespace aos
+}  // namespace aos::testing
diff --git a/aos/containers/priority_queue_test.cc b/aos/containers/priority_queue_test.cc
index 64456c4..f27a206 100644
--- a/aos/containers/priority_queue_test.cc
+++ b/aos/containers/priority_queue_test.cc
@@ -2,8 +2,7 @@
 
 #include "gtest/gtest.h"
 
-namespace aos {
-namespace testing {
+namespace aos::testing {
 
 // Effectively copies the implementation of ::std::less just to demonstrate how
 // things work.
@@ -172,5 +171,4 @@
   EXPECT_EQ(11, it->a);
 }
 
-}  // namespace testing
-}  // namespace aos
+}  // namespace aos::testing
diff --git a/aos/containers/ring_buffer_test.cc b/aos/containers/ring_buffer_test.cc
index b4cf1fb..c06ef0e 100644
--- a/aos/containers/ring_buffer_test.cc
+++ b/aos/containers/ring_buffer_test.cc
@@ -3,8 +3,7 @@
 #include "glog/logging.h"
 #include "gtest/gtest.h"
 
-namespace aos {
-namespace testing {
+namespace aos::testing {
 
 // A class which is implicitly convertible to and from int, and tracks object
 // lifetimes.
@@ -206,5 +205,4 @@
   EXPECT_EQ(i, buffer_.size());
 }
 
-}  // namespace testing
-}  // namespace aos
+}  // namespace aos::testing
diff --git a/aos/containers/sized_array_test.cc b/aos/containers/sized_array_test.cc
index d055f40..645d669 100644
--- a/aos/containers/sized_array_test.cc
+++ b/aos/containers/sized_array_test.cc
@@ -2,8 +2,7 @@
 
 #include "gtest/gtest.h"
 
-namespace aos {
-namespace testing {
+namespace aos::testing {
 
 // Tests the various ways of accessing elements.
 TEST(SizedArrayTest, ElementAccess) {
@@ -240,5 +239,4 @@
   EXPECT_EQ(a.size(), 1);
 }
 
-}  // namespace testing
-}  // namespace aos
+}  // namespace aos::testing