Hook up stats reporting via default system on OS X.

Hook up stats reporting via default system on OS X.

Allow enabling/disabling stats via user defaults.
Fix breakpad to read from global stats setting.

To disable stats, type the following in the terminal:
defaults write com.google.Chrome usagestats -bool NO

BUG=12046

[pink (ping after 24hrs), 2009-05-18 21:21:09]

drive-by review.

http://codereview.chromium.org/113549/diff/1/4
File chrome/browser/google_update_settings_mac.mm (right):

http://codereview.chromium.org/113549/diff/1/4#newcode31
Line 31: if (val == nil || ![val respondsToSelector:@selector(boolValue)]) {
nil check not needed.

[John Grabowski, 2009-05-18 21:49:50]

http://codereview.chromium.org/113549/diff/1/4
File chrome/browser/google_update_settings_mac.mm (right):

http://codereview.chromium.org/113549/diff/1/4#newcode25
Line 25: // Declared in a public namespace for testing purposes.
Extra comments:
// If pref not set, assume yes

http://codereview.chromium.org/113549/diff/1/4#newcode26
Line 26: bool GetCollectStatsConsentFromDictionary(NSDictionary *dict) {
NSDictionary * --> NSDictionary*
NSString * --> NSString*
NSNumber * --> NSNumber*
...

http://codereview.chromium.org/113549/diff/1/5
File chrome/browser/google_update_settings_mac_unittest.mm (right):

http://codereview.chromium.org/113549/diff/1/5#newcode24
Line 24: TEST_F(GoogleUpdateTest, StatsConstent) {
Excellent

http://codereview.chromium.org/113549/diff/1/5#newcode28
Line 28: NSDictionary *empty_dict = [NSDictionary dictionary];
Blah * --> Blah*
in lots of places here

http://codereview.chromium.org/113549/diff/1/5#newcode47
Line 47: 
Stat not set test (which will be the most common case...)

[John Grabowski, 2009-05-18 21:52:33]

>> Stat not set test (which will be the most common case...)

Doh... is at the top of the file.

LGTM; rest are nits