Simulate transient error and verify exponential backoff.

chrome/browser/sync/profile_sync_service_harness.h

Index: chrome/browser/sync/profile_sync_service_harness.h
diff --git a/chrome/browser/sync/profile_sync_service_harness.h b/chrome/browser/sync/profile_sync_service_harness.h
index 4423e87bd162746f32a19ed35388ce2a32e5b1a2..ba19862c483421ae1cfd8d9bd402bf7e9a0e6d06 100644
--- a/chrome/browser/sync/profile_sync_service_harness.h
+++ b/chrome/browser/sync/profile_sync_service_harness.h
@@ -12,6 +12,7 @@
 #include "base/basictypes.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_service_observer.h"
+#include "chrome/browser/sync/retry_verifier.h"
 #include "chrome/browser/sync/syncable/model_type.h"
 
 class Profile;
@@ -76,6 +77,9 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
   // true if sync is disabled.
   bool AwaitSyncDisabled(const std::string& reason);
 
+  // Blocks the caller until exponential back off has been verified to happen.
+  bool AwaitExponentialBackoffVerification();
+
   // Blocks the caller until this harness has observed that the sync engine
   // has downloaded all the changes seen by the |partner| harness's client.
   bool WaitUntilTimestampMatches(
@@ -190,6 +194,16 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
     // The sync client is waiting for the sync to be disabled for this client.
     WAITING_FOR_SYNC_DISABLED,
 
+    // The client is in the exponential back off mode. Verify that backoffs are

[Raghu Simha, 2011/08/05 18:04:52]

s/The client/The sync client/

[lipalani1, 2011/08/05 21:33:57]

Done.

+    // triggered correctly.
+    WAITING_FOR_EXPONENTIAL_BACKOFF_VERIFICATION,
+
+    // Exponential backoff was triggered correctly.
+    EXPONENTIAL_BACKOFF_VERIFICATION_SUCEEDED,

[Raghu Simha, 2011/08/05 18:04:52]

Get rid of the SUCCEEDED and FAILED states. Other methods in this class that use
WAITING_FOR_* states figure out whether they've succeeded or failed by querying
internal state variables after SignalStateCompleteWithNextState has been called.
If we add 3 states per method, the number of wait states will become intractable
over time.

[lipalani1, 2011/08/05 21:33:57]

Done.

+
+    // Exponential backoff was NOT triggered correctly.
+    EXPONENTIAL_BACKOFF_VERIFICATION_FAILED,
+
     // The sync client needs a passphrase in order to decrypt data.
     SET_PASSPHRASE_FAILED,
 
@@ -262,6 +276,9 @@ class ProfileSyncServiceHarness : public ProfileSyncServiceObserver {
   // Used for logging.
   const std::string profile_debug_name_;
 
+  // Keep track of the retries for verification.

[Raghu Simha, 2011/08/05 18:04:52]

Perhaps a more descriptive comment like "Keeps track of the number of attempts
at exponential backoff."?

[lipalani1, 2011/08/05 21:33:57]

Done.

+  RetryVerifier retry_verifier_;
+
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncServiceHarness);
 };