Add --no-aosp flag to select Google Style

core/src/main/java/com/google/googlejavaformat/java/CommandLineOptionsParser.java

@@ -72,6 +72,7 @@ static CommandLineOptions parse(Iterable<String> options) {
         case "--offset", "-offset" -> optionsBuilder.addOffset(parseInteger(it, flag, value));
         case "--length", "-length" -> optionsBuilder.addLength(parseInteger(it, flag, value));
         case "--aosp", "-aosp", "-a" -> optionsBuilder.aosp(true);
+        case "--no-aosp", "-no-aosp" -> optionsBuilder.aosp(false);
         case "--version", "-version", "-v" -> optionsBuilder.version(true);
         case "--help", "-help", "-h" -> optionsBuilder.help(true);
         case "--fix-imports-only" -> optionsBuilder.fixImportsOnly(true);

core/src/main/java/com/google/googlejavaformat/java/UsageException.java

@@ -36,6 +36,9 @@ final class UsageException extends Exception {
     File name to use for diagnostics when formatting standard input (default is <stdin>).
   --aosp, -aosp, -a
     Use AOSP style instead of Google Style (4-space indentation).
+  --no-aosp, -no-aosp
+    Use Google Style (2-space indentation). If both --aosp and --no-aosp are given, the last
+    one wins.
   --fix-imports-only
     Fix import order and remove any unused imports, but do no other formatting.
   --skip-sorting-imports

core/src/test/java/com/google/googlejavaformat/java/CommandLineOptionsParserTest.java

@@ -77,6 +77,15 @@ public void aosp() {
     assertThat(CommandLineOptionsParser.parse(Arrays.asList("-aosp")).aosp()).isTrue();
   }
 
+  @Test
+  public void noAosp() {
+    assertThat(CommandLineOptionsParser.parse(Arrays.asList("--no-aosp")).aosp()).isFalse();
+    assertThat(CommandLineOptionsParser.parse(Arrays.asList("--aosp", "--no-aosp")).aosp())
+        .isFalse();
+    assertThat(CommandLineOptionsParser.parse(Arrays.asList("--no-aosp", "--aosp")).aosp())
+        .isTrue();
+  }
+
   @Test
   public void help() {
     assertThat(CommandLineOptionsParser.parse(Arrays.asList("-help")).help()).isTrue();