get_concurrent_links: Stop honoring GYP_LINK_CONCURRENCY

gyp is long long gone. Hopefully nobody still set this.
(If you do: Set the concurrent_links gn arg instead.)

Bug: none
Change-Id: Ifef44f50825c15d89dff95af7597944bfdf87da0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2449935
Auto-Submit: Nico Weber <thakis@chromium.org>
Commit-Queue: Dirk Pranke <dpranke@google.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Cr-Commit-Position: refs/heads/master@{#813973}

build/toolchain/get_concurrent_links.py

@@ -62,31 +62,23 @@ def _GetDefaultConcurrentLinks(per_link_gb, reserve_gb, secondary_per_link_gb):
   explanation.append(
       'per_link_gb={} reserve_gb={} secondary_per_link_gb={}'.format(
           per_link_gb, reserve_gb, secondary_per_link_gb))
-  # Inherit the legacy environment variable for people that have set it in GYP.
-  num_links = int(os.getenv('GYP_LINK_CONCURRENCY', 0))
-  if num_links:
-    reason = 'GYP_LINK_CONCURRENCY'
-  else:
-    mem_total_gb = float(_GetTotalMemoryInBytes()) / 2**30
-    mem_total_gb = max(0, mem_total_gb - reserve_gb)
-    mem_cap = int(max(1, mem_total_gb / per_link_gb))
-    hard_cap = max(1, int(os.getenv('GYP_LINK_CONCURRENCY_MAX', 2**32)))
+  mem_total_gb = float(_GetTotalMemoryInBytes()) / 2**30
+  mem_total_gb = max(0, mem_total_gb - reserve_gb)
+  mem_cap = int(max(1, mem_total_gb / per_link_gb))
 
-    try:
-      cpu_cap = multiprocessing.cpu_count()
-    except:
-      cpu_cap = 1
-
-    explanation.append('cpu_count={} mem_total_gb={:.1f}GiB'.format(
-        cpu_cap, mem_total_gb))
-
-    num_links = min(mem_cap, hard_cap, cpu_cap)
-    if num_links == cpu_cap:
-      reason = 'cpu_count'
-    elif num_links == hard_cap:
-      reason = 'GYP_LINK_CONCURRENCY_MAX'
-    else:
-      reason = 'RAM'
+  try:
+    cpu_cap = multiprocessing.cpu_count()
+  except:
+    cpu_cap = 1
+
+  explanation.append('cpu_count={} mem_total_gb={:.1f}GiB'.format(
+      cpu_cap, mem_total_gb))
+
+  num_links = min(mem_cap, cpu_cap)
+  if num_links == cpu_cap:
+    reason = 'cpu_count'
+  else:
+    reason = 'RAM'
 
   explanation.append('concurrent_links={}  (reason: {})'.format(
       num_links, reason))