Convert the browsing_data pyauto tests to chrome tests. Remove the ClearBrowsingData automation cod…

Convert the browsing_data pyauto tests to chrome tests. Remove the ClearBrowsingData automation code since it's not used anymore.

-browsing_data.testClearAutofillData was flaky because it exposed an actual problem in BrowsingDataRemover (it didn't wait for autofill data to be deleted). Fixed BrowsingDataRemover and added a unittest for removing form data along with the other BrowsingDataRemover unit tests.
-browsing_data.testClearDownloads was hard to write as a unit test so I added a browser test
-database.testDeleteAndUpdateDatabase was also converted to a browser test
-the rest of the tests in browsing_data.py had equivalent unit tests in browsing_data_remover_unittest.cc
-the clear password calls in the passwords test aren't needed since each test has a fresh profile

Also fix a flake in the BrowsingDataRemoverTest harness. The end time needs to be pushed further into the future, since there could be pending writes.

BUG=143637, 141443, 95165, 123419
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=152782

[Ben Goodger (Google), 2012-08-22 15:57:44]

lgtm

http://codereview.chromium.org/10866013/diff/5005/chrome/browser/browsing_dat...
File chrome/browser/browsing_data/browsing_data_remover_unittest.cc (right):

http://codereview.chromium.org/10866013/diff/5005/chrome/browser/browsing_dat...
chrome/browser/browsing_data/browsing_data_remover_unittest.cc:329:
~RemoveAutofillTester() {
virtual dtor?