Build with the system NSPR library instead of the bundled version.

Originally based on this Debian patch:
https://salsa.debian.org/chromium-team/chromium/-/blob/master/debian/patches/system/nspr.patch

diff --git a/base/BUILD.gn b/base/BUILD.gn
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -184,6 +184,12 @@ buildflag_header("ios_cronet_buildflags") {
   flags = [ "CRONET_BUILD=$is_cronet_build" ]
 }
 
+if (is_linux) {
+  ldflags = [
+    "-lnspr4",
+  ]
+}
+
 # Base and everything it depends on should be a static library rather than
 # a source set. Base is more of a "library" in the classic sense in that many
 # small parts of it are used in many different contexts. This combined with a
@@ -838,8 +844,6 @@ mixed_component("base") {
     "third_party/cityhash_v103/src/city_v103.cc",
     "third_party/cityhash_v103/src/city_v103.h",
     "third_party/icu/icu_utf.h",
-    "third_party/nspr/prtime.cc",
-    "third_party/nspr/prtime.h",
     "third_party/superfasthash/superfasthash.c",
     "thread_annotations.h",
     "threading/hang_watcher.cc",
diff --git a/base/time/pr_time_unittest.cc b/base/time/pr_time_unittest.cc
--- a/base/time/pr_time_unittest.cc
+++ b/base/time/pr_time_unittest.cc
@@ -6,7 +6,7 @@
 #include <time.h>
 
 #include "base/compiler_specific.h"
-#include "base/third_party/nspr/prtime.h"
+#include <nspr/prtime.h>
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "testing/gtest/include/gtest/gtest.h"
diff --git a/base/time/time.cc b/base/time/time.cc
--- a/base/time/time.cc
+++ b/base/time/time.cc
@@ -21,7 +21,7 @@
 #include <utility>
 
 #include "base/strings/stringprintf.h"
-#include "base/third_party/nspr/prtime.h"
+#include <nspr/prtime.h>
 #include "base/time/time_override.h"
 #include "build/build_config.h"
 #include "third_party/abseil-cpp/absl/types/optional.h"
ect>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=46fbb3e498c804636d9092c389f8c75eff20e120'>root</a>/<a href='/guix/log/tests?id=46fbb3e498c804636d9092c389f8c75eff20e120'>tests</a>/<a href='/guix/log/tests/builders.scm?id=46fbb3e498c804636d9092c389f8c75eff20e120'>builders.scm</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/tests/builders.scm?id=46fbb3e498c804636d9092c389f8c75eff20e120&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2022-10-22 01:46:55 +0200'>2022-10-22</span></td><td><a href='/guix/commit/tests/builders.scm?id=a3619079f95213c4f983e69210ed12b38fd31022'>Remove now unnecessary uses of (guix grafts).</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-09-17 01:27:40 +0200'>2021-09-17</span></td><td><a href='/guix/commit/tests/builders.scm?id=f62e47df8d4b5a9129de8d220eb380673cc1729a'>tests: Add missing module import.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>
<tr><td><span title='2021-09-07 14:44:39 +0200'>2021-09-07</span></td><td><a href='/guix/commit/tests/builders.scm?id=9bea983e4f5a1c07737336163bc6835f6c582a6e'>tests: Disable grafts in 'tests/builders.scm'.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-07-05 15:41:45 +0200'>2021-07-05</span></td><td><a href='/guix/commit/tests/builders.scm?id=d8fdd1c74a59730d174577aa7c2c8de73715da8e'>tests: Adjust Python "sanity" check tests.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-03-30 22:48:43 +0200'>2021-03-30</span></td><td><a href='/guix/commit/tests/builders.scm?id=7d873f194ca69d6096d28d7a224ab78e83e34fe1'>build-system: Rewrite using gexps.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2021-02-01 11:53:43 -0500'>2021-02-01</span></td><td><a href='/guix/commit/tests/builders.scm?id=09448c0994390697e876db235a3b773311795238'>build/python: Add a sanity check phase.</a><span class='msg-avail'>...</span></td><td>Lars-Dominik Braun</td></tr>
<tr><td><span title='2021-01-26 22:48:35 -0500'>2021-01-26</span></td><td><a href='/guix/commit/tests/builders.scm?id=cfcead2e515c0dae02127e5a76496463898be6b6'>build-systems/gnu: Allow unpacking/repacking more kind of files.</a><span class='msg-avail'>...</span></td><td>Maxim Cournoyer</td></tr>
<tr><td><span title='2019-06-14 21:57:18 +0200'>2019-06-14</span></td><td><a href='/guix/commit/tests/builders.scm?id=11b4a8716c65e8fe21e5975e764b3e14dbd8dcc4'>tests: Remove expensive and pointless test.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-09-22 22:40:12 +0200'>2018-09-22</span></td><td><a href='/guix/commit/tests/builders.scm?id=a2b2070b679ff7e92d856c7d6775f5f67ce4792d'>bootstrap: %bootstrap-inputs: Wrap input lists into thunks.</a><span class='msg-avail'>...</span></td><td>Jan Nieuwenhuizen</td></tr>
<tr><td><span title='2018-09-04 17:25:11 +0200'>2018-09-04</span></td><td><a href='/guix/commit/tests/builders.scm?id=ca719424455465fca4b872c371daf2a46de88b33'>Switch to Guile-Gcrypt.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>