Generating CIDs in Blink during MHTML serialization.

chrome/android/javatests/src/org/chromium/chrome/browser/offlinepages/OfflinePageBridgeTest.java

 // 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.
 
 package org.chromium.chrome.browser.offlinepages;
 
 import android.test.suitebuilder.annotation.MediumTest;
 
 import org.chromium.base.ThreadUtils;
 import org.chromium.chrome.browser.ChromeActivity;
@@ skipping 73 matching lines @@
         assertEquals("Offline pages count incorrect.", 1, allPages.size());
         assertEquals("Offline page item url incorrect.", TEST_PAGE, offlinePage.getUrl());
         assertEquals("Offline page item bookmark ID incorrect.", BOOKMARK_ID,
                 offlinePage.getBookmarkId());
         assertTrue("Offline page item offline file url doesn't start properly.",
                 offlinePage.getOfflineUrl().startsWith("file:///"));
         assertTrue("Offline page item offline file doesn't have the right name.",
                 offlinePage.getOfflineUrl().endsWith(".mhtml"));
         assertTrue("Offline page item offline file doesn't have the right name.",
                 offlinePage.getOfflineUrl().contains("About"));
-        // BUG(518758): Depending on the bot the result will be either 626 or 627.
+
+        // We don't care about the exact file size of the mhtml file:
+        // - exact file size is not something that the end user sees or cares about
+        // - exact file size can vary based on external factors (i.e. see crbug.com/518758)
+        // - verification of contents of the resulting mhtml file should be covered by mhtml
+        //   serialization tests (i.e. save_page_browsertest.cc)
+        // - we want to avoid overtesting and artificially requiring specific formatting and/or
+        //   implementation choices in the mhtml serialization code
+        // OTOH, it still seems useful to assert that the file is not empty and that its size is in
+        // the right ballpark.
         long size = offlinePage.getFileSize();
-        assertTrue("Offline page item size is incorrect: " + size, size == 626 || size == 627);
+        assertTrue("Offline page item size is incorrect: " + size, 600 < size && size < 800);
     }
 
     @MediumTest
     public void testMarkPageAccessed() throws Exception {
         loadUrl(TEST_PAGE);
         savePage(SavePageResult.SUCCESS, TEST_PAGE);
         OfflinePageItem offlinePage = mOfflinePageBridge.getPageByBookmarkId(BOOKMARK_ID);
         assertNotNull("Offline page should be available, but it is not.", offlinePage);
         assertEquals("Offline page access count should be 0.", 0, offlinePage.getAccessCount());
 
@@ skipping 107 matching lines @@
                     result.add(item);
                 }
 
                 semaphore.release();
             }
         });
         assertTrue(semaphore.tryAcquire(TIMEOUT_MS, TimeUnit.MILLISECONDS));
         return result;
     }
 }