android: Pass (non-generated) .java files via a gyp filelist to javac.py

build/java_apk.gypi

Index: build/java_apk.gypi
diff --git a/build/java_apk.gypi b/build/java_apk.gypi
index f9387cd2d6675bc98c5bfeddda2d52a99e1a205b..0431f9d74423e84b1022cd6dbf85ff3f688071cc 100644
--- a/build/java_apk.gypi
+++ b/build/java_apk.gypi
@@ -513,19 +513,27 @@
       'action_name': 'javac_<(_target_name)',
       'message': 'Compiling java for <(_target_name)',
       'variables': {
-        'all_src_dirs': [
-          '<(java_in_dir)/src',
+        'gen_src_dirs': [
           '<(intermediate_dir)/gen',
-          '>@(additional_src_dirs)',
           '>@(generated_src_dirs)',
         ],
+        # If there is a separate find for additional_src_dirs, it will find the
+        # wrong .java files when additional_src_dirs is empty.
+        # TODO(thakis): Gyp caches >! evaluation by command. Both java.gypi and
+        # java_apk.gypi evaluate the same command, and at the moment two targets
+        # set java_in_dir to "java". Add a dummy comment here to make sure
+        # that the two targets (one uses java.gypi, the other java_apk.gypi)
+        # get distinct source lists. Medium-term, make targets list all their
+        # Java files instead of using find. (As is, this will be broken if two
+        # targets use the same java_in_dir and both use java_apk.gypi or
+        # both use java.gypi.)
+        'java_source_list': '>|(javasources.<(_target_name).gypcmd >!@(find >(java_in_dir)/src >(additional_src_dirs) -name "*.java"  # apk))',
+
       },
       'inputs': [
         '<(DEPTH)/build/android/gyp/util/build_utils.py',
         '<(DEPTH)/build/android/gyp/javac.py',
-        # If there is a separate find for additional_src_dirs, it will find the
-        # wrong .java files when additional_src_dirs is empty.
-        '>!@(find >(java_in_dir) >(additional_src_dirs) -name "*.java")',
+        '>(java_source_list)',
         '>@(input_jars_paths)',
         '<(codegen_stamp)',
         '>@(compile_input_paths)',
@@ -537,7 +545,8 @@
         'python', '<(DEPTH)/build/android/gyp/javac.py',
         '--output-dir=<(classes_dir)',
         '--classpath=>(input_jars_paths) <(android_sdk_jar)',
-        '--src-dirs=>(all_src_dirs)',
+        '--src-filelist=>(java_source_list)',
+        '--src-gendirs=>(gen_src_dirs)',
         '--javac-includes=<(javac_includes)',
         '--chromium-code=<(chromium_code)',
         '--stamp=<(compile_stamp)',