Use multiple IDs when discarding or merging snippets.

components/ntp_snippets/ntp_snippets_service_unittest.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/ntp_snippets/ntp_snippets_service.h"
 
 #include <memory>
 #include <vector>
 
 #include "base/command_line.h"
@@ skipping 758 matching lines @@
                           base::Bucket(/*min=*/1, /*count=*/3)));
   EXPECT_THAT(
       tester.GetAllSamples("NewTabPage.Snippets.NumArticlesZeroDueToDiscarded"),
       ElementsAre(base::Bucket(/*min=*/1, /*count=*/1)));
   // Recreating the service and loading from prefs shouldn't count as fetched
   // articles.
   EXPECT_CALL(mock_scheduler(), Schedule(_, _, _, _)).Times(1);
   CreateSnippetsService(/*enabled=*/true);
   tester.ExpectTotalCount("NewTabPage.Snippets.NumArticlesFetched", 4);
 }
+
+const char kChromeReaderResponseMultipleUrls[] =
+    "{ \"recos\": [{ "
+    "  \"contentInfo\": { "
+    "    \"url\": \"%s\", "
+    "    \"creationTimestampSec\": \"%s\", "
+    "    \"expiryTimestampSec\" : \"%s\","
+    "    \"title\": \"Stolen doggie finally gets returned to owner after two "
+    "years\", "

[Marc Treib, 2016/05/18 18:58:05]

One more avoidable line break :)

[tschumann, 2016/05/18 19:23:29]

Done.

+    "    \"snippet\": \"It\'s at least this man\'s best friend.\", "
+    "    \"thumbnailUrl\": \"http://t0.gstatic.com/images?q=tbn:1\", "
+    "    \"sourceCorpusInfo\": [{"
+    "      \"type\" : \"CHROME_LOGS\", "
+    "      \"corpusId\": \"http://mashable.com/2016/05/11/stolen\", "
+    "      \"publisherData\": { "
+    "        \"sourceName\": \"Mashable\", "
+    "        \"sourceLogoUrl\": \"http://t3.gstatic.com/images?q=tbn:2\" "
+    "      }, "
+    "      \"ampUrl\": \"http://mashable-amphtml.googleusercontent.com/1\" "
+    "    }, { "
+    "      \"type\": \"CHROME_LOGS\", "
+    "      \"corpusId\": \"http://www.aol.com/article/2016/05/stolen-doggie\", "
+    "      \"publisherData\":  { "
+    "        \"sourceName\": \"AOL\", "
+    "        \"sourceLogoUrl\": \"http://t2.gstatic.com/images?q=tbn:3\" "
+    "      }, "
+    "      \"ampUrl\": \"http://mashable-amphtml.googleusercontent.com/1\" "
+    "    }, { "
+    "      \"type\": \"CHROME_LOGS\", "
+    "      \"corpusId\": \"http://mashable.com/2016/05/11/stolen?utm_cid=1\", "
+    "      \"publisherData\": { "
+    "        \"sourceName\": \"Mashable\", "
+    "        \"sourceLogoUrl\": \"http://t3.gstatic.com/images?q=tbn:2\" "
+    "      }, "
+    "      \"ampUrl\": \"http://mashable-amphtml.googleusercontent.com/1\" "
+    "    }] "
+    "  }, "
+    "  \"score\" : \"0.099307865\" "
+    "}]} ";
+
+TEST_F(NTPSnippetsServiceTest, DiscardShouldRespectAllKnownUrls) {
+  const std::string url_mashable = "http://mashable.com/2016/05/11/stolen";
+  const std::string url_aol =
+      "http://www.aol.com/article/2016/05/stolen-doggie";
+
+  LoadFromJSONString(base::StringPrintf(
+      kChromeReaderResponseMultipleUrls, url_mashable.c_str(),
+      NTPSnippet::TimeToJsonString(GetDefaultCreationTime()).c_str(),
+      NTPSnippet::TimeToJsonString(base::Time::Now() +
+                                   base::TimeDelta::FromHours(1))
+          .c_str()));
+  ASSERT_THAT(service()->snippets(), SizeIs(1));
+  // Discard the snippet via the mashable source corpus ID.
+  EXPECT_TRUE(service()->DiscardSnippet(url_mashable));
+  EXPECT_THAT(service()->snippets(), IsEmpty());
+
+  // The same article from the AOL domain should now be detected as discarded.
+  LoadFromJSONString(base::StringPrintf(
+      kChromeReaderResponseMultipleUrls, url_aol.c_str(),
+      NTPSnippet::TimeToJsonString(GetDefaultCreationTime()).c_str(),
+      NTPSnippet::TimeToJsonString(base::Time::Now() +
+                                   base::TimeDelta::FromHours(1))
+          .c_str()));
+  ASSERT_THAT(service()->snippets(), IsEmpty());
+}
+
 }  // namespace ntp_snippets