Revert "Dexpreopt: prepare to merge class loader context from al..."

Reason for revert: performance regression on AppStartup.
Reverted Changes:
I6522319a8:Dexpreopt: prepare to merge class loader context f...
Ic8528dffd:manifest_check.py: add uses-libraries propagaged v...

Bug: 235304939
Bug: 214255490
Change-Id: Iff6ad6f0d862df259bf9e3dd7017c268dbcbf8bf

core/dex_preopt_config_merger.py

@@ -31,7 +31,6 @@ from __future__ import print_function
 
 import json
 from collections import OrderedDict
-import os
 import sys
 
 
@@ -43,9 +42,8 @@ def main():
   # Read all JSON configs.
   cfgs = []
   for arg in sys.argv[1:]:
-    if os.stat(arg).st_size != 0:
-      with open(arg, 'r') as f:
-        cfgs.append(json.load(f, object_pairs_hook=OrderedDict))
+    with open(arg, 'r') as f:
+      cfgs.append(json.load(f, object_pairs_hook=OrderedDict))
 
   # The first config is the dexpreopted library/app, the rest are its
   # <uses-library> dependencies.
@@ -90,33 +88,6 @@ def main():
       clcs2.append(clc)
     clc_map2[sdk_ver] = clcs2
 
-  # Go over all uses-libraries in dependency dexpreopt.config files (these don't
-  # have to be uses-libraries themselves, they can be e.g. transitive static
-  # library dependencies) and merge their CLC to the current one
-  for ulib, cfg in uses_libs.items():
-    any_sdk_ver = 'any' # not interested in compatibility libraries
-    clcs = cfg['ClassLoaderContexts'].get(any_sdk_ver, [])
-
-    # If the dependency is a uses-library itself, its uses-library dependencies
-    # are added as a subcontext, so don't add them to top-level CLC.
-    dep_is_a_uses_lib = False
-    for clc2 in clc_map2[any_sdk_ver]:
-      if clc2['Name'] == cfg['ProvidesUsesLibrary']:
-        dep_is_a_uses_lib = True
-    if dep_is_a_uses_lib:
-      continue
-
-    # Check if CLC for these libraries is already present (avoid duplicates).
-    # Don't bother optimizing quadratic loop, since CLC is typically small.
-    for clc in clcs:
-      already_in_clc = False
-      for clc2 in clc_map2[any_sdk_ver]:
-        if clc2['Name'] == clc['Name']:
-          already_in_clc = True
-          break
-      if not already_in_clc:
-        clc_map2[any_sdk_ver] += clcs
-
   # Overwrite the original class loader context with the patched one.
   cfg0['ClassLoaderContexts'] = clc_map2