Fix stale mojom-generated Java problems with gyp builds

third_party/mojo/mojom_bindings_generator.gypi

Index: third_party/mojo/mojom_bindings_generator.gypi
diff --git a/third_party/mojo/mojom_bindings_generator.gypi b/third_party/mojo/mojom_bindings_generator.gypi
index e58aab34401e2c543761f89f17d26e914c132e6f..43d7f714de7959fe5026268510a2301c9a201af4 100644
--- a/third_party/mojo/mojom_bindings_generator.gypi
+++ b/third_party/mojo/mojom_bindings_generator.gypi
@@ -6,6 +6,22 @@
   'includes': [
     'mojom_bindings_generator_variables.gypi',
   ],
+  'actions': [
+    {
+      'variables': {
+        'java_out_dir': '<(PRODUCT_DIR)/java_mojo/<(_target_name)/src',
+        'stamp_filename': '<(PRODUCT_DIR)/java_mojo/<(_target_name)/<(_target_name).stamp',
+      },
+      'action_name': '<(_target_name)_mojom_bindings_stamp',

[cjhopman, 2015/02/26 02:15:36]

this could probably use a really short comment about why:

# The java output directory is deleted to ensure that the java library doesn't
try to compile stale files.

[Ken Rockot(use gerrit already), 2015/02/26 02:36:16]

Done.

+      'action': [
+        'python', '<(DEPTH)/build/rmdir_and_stamp.py',
+        '<(java_out_dir)',
+        '<(stamp_filename)',
+      ],
+      'inputs': [ '<@(_sources)' ],
+      'outputs': [ '<(stamp_filename)' ],
+    }
+  ],
   'rules': [
     {
       'rule_name': '<(_target_name)_mojom_bindings_generator',
@@ -18,9 +34,11 @@
          '-I<(DEPTH)',
          '-I<(DEPTH)/third_party/mojo/src'
         ],
+        'stamp_filename': '<(PRODUCT_DIR)/java_mojo/<(_target_name)/<(_target_name).stamp',
       },
       'inputs': [
         '<@(mojom_bindings_generator_sources)',
+        '<(stamp_filename)',
       ],
       'outputs': [
         '<(SHARED_INTERMEDIATE_DIR)/<(mojom_base_output_dir)/<(RULE_INPUT_DIRNAME)/<(RULE_INPUT_ROOT).mojom.cc',