Fixed Vivek's bug (#5860)

* Fixed Vivek's bug

Fixes #5850

What was happening:

It seems that his MetaMask had crashed while some new transactions had
been loading defaults. He probably had a network connectivity issue to
Infura (which we are working with Infura to address).

As a result of this network cutout, his three unapproved transactions
were not marked failed, and were not marked as `loadingDefaults =
false`, as their gas prices had not yet been estimated.

Normally this behavior is supposed to clean itself up when the
transaction controller starts up, via the
`TransactionController._onBootCleanUp()` function, but in this case,
during unlock, that function was unable to do its job because when it
requested the transaction list, the current network was in the `loading`
state, making it proceed as if there were no pending transactions.

To fix this, I am doing two things:
- Setting transactions to loadingDefaults = false in more catch blocks.
- Calling `onBootCleanUp()` when the network store's status changes, so
that it will re-trigger when loading completes.

* Fixed reference

* Fixed infinite loop bug

Was refreshing the tx list on every tx state change instead of just
network changes, creating an infinite loop.

* Add notes to tx updates to clarify logs

app/scripts/controllers/transactions/index.js

@@ -96,7 +96,10 @@ class TransactionController extends EventEmitter {
     // memstore is computed from a few different stores
     this._updateMemstore()
     this.txStateManager.store.subscribe(() => this._updateMemstore())
-    this.networkStore.subscribe(() => this._updateMemstore())
+    this.networkStore.subscribe(() => {
+      this._onBootCleanUp()
+      this._updateMemstore()
+    })
     this.preferencesStore.subscribe(() => this._updateMemstore())
 
     // request state update to finalize initialization
@@ -191,10 +194,13 @@ class TransactionController extends EventEmitter {
       txMeta = await this.addTxGasDefaults(txMeta)
     } catch (error) {
       log.warn(error)
-      this.txStateManager.setTxStatusFailed(txMeta.id, error)
+      txMeta.loadingDefaults = false
+      this.txStateManager.updateTx(txMeta, 'Failed to calculate gas defaults.')
       throw error
     }
+
     txMeta.loadingDefaults = false
+
     // save txMeta
     this.txStateManager.updateTx(txMeta)
 
@@ -485,6 +491,8 @@ class TransactionController extends EventEmitter {
         txMeta.loadingDefaults = false
         this.txStateManager.updateTx(txMeta, 'transactions: gas estimation for tx on boot')
       }).catch((error) => {
+        tx.loadingDefaults = false
+        this.txStateManager.updateTx(tx, 'failed to estimate gas during boot cleanup.')
         this.txStateManager.setTxStatusFailed(tx.id, error)
       })
     })