Refactor sync passphrase setup flow and fix passphrase tests

chrome/browser/sync/engine/syncapi.h

Index: chrome/browser/sync/engine/syncapi.h
diff --git a/chrome/browser/sync/engine/syncapi.h b/chrome/browser/sync/engine/syncapi.h
index 1011a299d6ca4d9697cf1f728e0231336fc41106..0e1f6b5f7a75db1cc0a387c38641238adf4a83cb 100644
--- a/chrome/browser/sync/engine/syncapi.h
+++ b/chrome/browser/sync/engine/syncapi.h
@@ -107,6 +107,35 @@ class HttpPostProviderFactory;
 class SyncManager;
 class WriteTransaction;
 
+// Reasons due to which browser_sync::Cryptographer might require a passphrase.
+enum PassphraseRequiredReason {
+  UNKNOWN = 0,               // Initial value
+  ENCRYPTION = 1,            // The cryptographer requires a passphrase for

[tim (not reviewing), 2011/04/29 01:21:48]

Since this is in the syncapi ns, we should probably do something like
REASON_ENCRYPTION
REASON_DECRYPTION...

sync_api::ENCRYPTION is kinda ambiguous

[Raghu Simha, 2011/04/29 18:59:14]

Done.

+                             // its first attempt at encryption.
+  DECRYPTION = 2,            // The cryptographer requires a passphrase for
+                             // its first attempt at decryption.
+  DECRYPTION_FAILED = 3,     // The cryptographer requires a new passphrase

[tim (not reviewing), 2011/04/29 01:21:48]

SET_PASSPHRASE_FAILED

[Raghu Simha, 2011/04/29 18:59:14]

Done.

+                             // because its attempt at decryption with the
+                             // cached passphrase was unsuccessful.
+};
+
+// Returns the string representation of a PassphraseRequiredReason value.
+std::string PassphraseRequiredReasonToString(PassphraseRequiredReason reason) {
+  switch (reason) {
+    case UNKNOWN:
+      return "UNKNOWN";
+    case ENCRYPTION:
+      return "ENCRYPTION";
+    case DECRYPTION:
+      return "DECRYPTION";
+    case DECRYPTION_FAILED:
+      return "DECRYPTION_FAILED";
+    default:
+      NOTREACHED();
+      return "INVALID_REASON";
+  }
+}
+
 // A UserShare encapsulates the syncable pieces that represent an authenticated
 // user and their data (share).
 // This encompasses all pieces required to build transaction objects on the
@@ -779,18 +808,12 @@ class SyncManager {
     virtual void OnUpdatedToken(const std::string& token) = 0;
 
     // Called when user interaction is required to obtain a valid passphrase.
-    // If the passphrase is required to decrypt something that has
-    // already been encrypted (and thus has to match the existing key),
-    // |for_decryption| will be true.  If the passphrase is needed for
-    // encryption, |for_decryption| will be false.
-    virtual void OnPassphraseRequired(bool for_decryption) = 0;
-
-    // Called only by SyncInternal::SetPassphrase to indiciate that an attempted
-    // passphrase failed to decrypt pending keys. This is different from
-    // OnPassphraseRequired in that it denotes we finished an attempt to set
-    // a passphrase. OnPassphraseRequired means we have data we could not
-    // decrypt yet, and can come from numerous places.
-    virtual void OnPassphraseFailed() = 0;
+    // - If the passphrase is required for encryption, |reason| is ENCRYPTION.
+    // - If the passphrase is required for the decryption of data that has
+    //   already been encrypted, |reason| will be DECRYPTION.
+    // - If the passphrase is required because decryption failed, and a new
+    //   passphrase is required, |reason| will be DECRYPTION_FAILED.
+    virtual void OnPassphraseRequired(PassphraseRequiredReason reason) = 0;
 
     // Called when the passphrase provided by the user has been accepted and is
     // now used to encrypt sync data.  |bootstrap_token| is an opaque base64