ninja: rules chained only by output of first one failing

pylib/gyp/generator/ninja.py

Index: pylib/gyp/generator/ninja.py
diff --git a/pylib/gyp/generator/ninja.py b/pylib/gyp/generator/ninja.py
index 8809edb88bfe6dd6bd123f6e75261904e9b8b34c..a2da524189bb9530ee7ece0a7ec01a713f3c7a7a 100644
--- a/pylib/gyp/generator/ninja.py
+++ b/pylib/gyp/generator/ninja.py
@@ -517,6 +517,22 @@ class NinjaWriter:
 
     return all_outputs
 
+  def _GetSourcesForRule(self, main_rule, all_rules):
+    """Get all sources that this rule needs to process. In addition to the
+    rule_sources we have to consider the outputs of other rules."""
+    sources = main_rule.get('rule_sources', [])
+    rule_ext = '.' + main_rule['extension']
+    for rule in all_rules:
+      if rule == main_rule:
+        continue
+      # If this rules outputs are processed, and they're something that this
+      # rule cares about, then add to the inputs.
+      if int(rule.get('process_outputs_as_sources', False)):
+        for output in rule['outputs']:
+          if output.endswith(rule_ext):
+            sources.append(output)
+    return sources
+
   def WriteRules(self, rules, extra_sources, prebuild,
                  extra_mac_bundle_resources):
     all_outputs = []
@@ -552,8 +568,9 @@ class NinjaWriter:
           return path.replace('\\', '/')
         return path
 
+      sources = self._GetSourcesForRule(rule, rules)
       # For each source file, write an edge that generates all the outputs.
-      for source in rule.get('rule_sources', []):
+      for source in sources:
         dirname, basename = os.path.split(source)
         root, ext = os.path.splitext(basename)