Grit: Fixes android_xml.py where translations have multiple same key plurals

Due to some bug within the translation pipeline, translated grd files
sometimes end up with multiple plural entries that have the same/similar
key, eg: '=1' and 'one'. This change makes sure that the xml output only
has one entry in per key. This is required by aapt2, which fails with an error
otherwise.

Bug: 787488
Change-Id: I6d98c1739a7dbd3872c31cbfca63b0bd5612c79d
Reviewed-on: https://chromium-review.googlesource.com/807148
Commit-Queue: Mohamed Heikal <mheikal@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Reviewed-by: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521888}

tools/grit/grit/format/android_xml.py

@@ -174,13 +174,17 @@ def _FormatPluralMessage(message):
     return None
   body_in = plural_match.group('items').strip()
   lines = []
+  quantities_so_far = set()
   for item_match in _PLURALS_ITEM_PATTERN.finditer(body_in):
     quantity_in = item_match.group('quantity')
     quantity_out = _PLURALS_QUANTITY_MAP.get(quantity_in)
     value_in = item_match.group('value')
     value_out = '"' + value_in.replace('#', '%d') + '"'
     if quantity_out:
-      lines.append(_PLURALS_ITEM_TEMPLATE % (quantity_out, value_out))
+      # only one line per quantity out (https://crbug.com/787488)
+      if quantity_out not in quantities_so_far:
+        quantities_so_far.add(quantity_out)
+        lines.append(_PLURALS_ITEM_TEMPLATE % (quantity_out, value_out))
     else:
       raise Exception('Unsupported plural quantity for android '
                       'strings.xml: %s' % quantity_in)

tools/grit/grit/format/android_xml_unittest.py

@@ -80,6 +80,34 @@ a sledge hammer."</string>
 """
     self.assertEqual(output.strip(), expected.strip())
 
+
+  def testConflictingPlurals(self):
+    root = util.ParseGrdForUnittest(ur"""
+        <messages>
+          <message name="IDS_PLURALS" desc="A string using the ICU plural format">
+            {NUM_THINGS, plural,
+            =1 {Maybe I'll get one laser.}
+            one {Maybe I'll get one laser.}
+            other {Maybe I'll get # lasers.}}
+          </message>
+        </messages>
+        """)
+
+    buf = StringIO.StringIO()
+    build.RcBuilder.ProcessNode(root, DummyOutput('android', 'en'), buf)
+    output = buf.getvalue()
+    expected = ur"""
+<?xml version="1.0" encoding="utf-8"?>
+<resources xmlns:android="http://schemas.android.com/apk/res/android">
+<plurals name="plurals">
+  <item quantity="one">"Maybe I\'ll get one laser."</item>
+  <item quantity="other">"Maybe I\'ll get %d lasers."</item>
+</plurals>
+</resources>
+"""
+    self.assertEqual(output.strip(), expected.strip())
+
+
   def testTaggedOnly(self):
     root = util.ParseGrdForUnittest(ur"""
         <messages>