Trichrome: Fix native library listing for component builds.

NativeLibraries.java has a dependency issue that creates problems for
Trichrome Webview 64 bit component builds.

This CL adds a workaround of these issues by just listing a single
native library, libmonochrome.cr.so, which does have the right
dependencies (listed in the "NEEDED" section of the binary).

The problem and fix both only affect trichrome component builds.

Bug: 1042107
Change-Id: Ib4873daeccf89373cacf1aace1240b6d708331f2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2008464Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Eric Stevenson <estevenson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734105}

build/android/gyp/write_native_libraries_java.py

@@ -15,6 +15,14 @@ from native_libraries_template import NATIVE_LIBRARIES_TEMPLATE
 from util import build_utils
 
 
+def _FormatLibraryName(library_name):
+  filename = os.path.split(library_name)[1]
+  assert filename.startswith('lib')
+  assert filename.endswith('.so')
+  # Remove lib prefix and .so suffix.
+  return '"%s"' % filename[3:-3]
+
+
 def main():
   parser = argparse.ArgumentParser()
 
@@ -46,6 +54,10 @@ def main():
       required=True,
       default='CPU_FAMILY_UNKNOWN',
       help='CPU family.')
+  parser.add_argument(
+      '--main-component-library',
+      help='If used, the list of native libraries will only contain this '
+      'library. Dependencies are found in the library\'s "NEEDED" section.')
 
   parser.add_argument(
       '--output', required=True, help='Path to the generated srcjar file.')
@@ -57,15 +69,14 @@ def main():
               'Must set --enable-chromium-linker to load library from APK.')
 
   native_libraries_list = []
-  if options.native_libraries_list:
+  if options.main_component_library:
+    native_libraries_list.append(
+        _FormatLibraryName(options.main_component_library))
+  elif options.native_libraries_list:
     with open(options.native_libraries_list) as f:
       for path in f:
         path = path.strip()
-        filename = os.path.split(path)[1]
-        assert filename.startswith('lib')
-        assert filename.endswith('.so')
-        # Remove lib prefix and .so suffix.
-        native_libraries_list.append('"%s"' % filename[3:-3])
+        native_libraries_list.append(_FormatLibraryName(path))
 
   def bool_str(value):
     if value:

build/config/android/rules.gni

@@ -716,6 +716,12 @@ if (enable_java_templates) {
             invoker.version_number,
           ]
         }
+        if (defined(invoker.main_component_library)) {
+          args += [
+            "--main-component-library",
+            invoker.main_component_library,
+          ]
+        }
         if (defined(invoker.enable_chromium_linker) &&
             invoker.enable_chromium_linker) {
           args += [ "--enable-chromium-linker" ]
@@ -2113,6 +2119,9 @@ if (enable_java_templates) {
   #     compiling sources given to this target (optional).
   #   bundles_supported: Enable Java code to treat this target as a bundle
   #     whether (by default determined by the target type).
+  #   main_component_library: Specifies the name of the base component's library
+  #     in a component build. If given, the system will find dependent native
+  #     libraries at runtime by inspecting this library (optional).
   template("android_apk_or_module") {
     forward_variables_from(invoker, [ "testonly" ])
     assert(defined(invoker.android_manifest))
@@ -2620,7 +2629,11 @@ if (enable_java_templates) {
         !_uses_static_library_synchronized_proguard
     if (_generate_native_libraries_java) {
       write_native_libraries_java("${_template_name}__native_libraries") {
-        forward_variables_from(invoker, [ "enable_chromium_linker_tests" ])
+        forward_variables_from(invoker,
+                               [
+                                 "enable_chromium_linker_tests",
+                                 "main_component_library",
+                               ])
         deps = [
           ":${_template_name}__secondary_abi_shared_library_list",
           ":${_template_name}__shared_library_list",
@@ -3412,6 +3425,7 @@ if (enable_java_templates) {
                                "manifest_package",
                                "max_sdk_version",
                                "product_config_java_packages",
+                               "main_component_library",
                                "min_sdk_version",
                                "native_lib_placeholders",
                                "native_lib_version_arg",

chrome/android/trichrome.gni

@@ -188,6 +188,11 @@ template("trichrome_library_apk_tmpl") {
       }
     }
 
+    # http://crbug.com/1042107.
+    if (is_component_build) {
+      main_component_library = "libmonochrome.cr.so"
+    }
+
     if (!is_java_debug) {
       proguard_enabled = true
       proguard_configs = [