Refactor eth-store into account-tracker

EthStore was only being used for tracking account balances and nonces now, so I removed its block-tracking duties, renamed it account-tracker, and removed it as a dependency from `KeyringController`, so that KRC can go live on without a hard dep on it.

app/scripts/controllers/computed-balances.js

@@ -2,7 +2,7 @@ const ObservableStore = require('obs-store')
 const extend = require('xtend')
 const BalanceController = require('./balance')
 
-class BalancesController {
+class ComputedbalancesController {
 
   constructor (opts = {}) {
     const { ethStore, txController } = opts
@@ -61,4 +61,4 @@ class BalancesController {
   }
 }
 
-module.exports = BalancesController
+module.exports = ComputedbalancesController

app/scripts/controllers/transactions.js

@@ -22,7 +22,7 @@ module.exports = class TransactionController extends EventEmitter {
     this.provider = opts.provider
     this.blockTracker = opts.blockTracker
     this.signEthTx = opts.signTransaction
-    this.ethStore = opts.ethStore
+    this.accountTracker = opts.accountTracker
 
     this.nonceTracker = new NonceTracker({
       provider: this.provider,
@@ -52,7 +52,7 @@ module.exports = class TransactionController extends EventEmitter {
       provider: this.provider,
       nonceTracker: this.nonceTracker,
       getBalance: (address) => {
-        const account = this.ethStore.getState().accounts[address]
+        const account = this.accountTracker.getState().accounts[address]
         if (!account) return
         return account.balance
       },
@@ -73,7 +73,7 @@ module.exports = class TransactionController extends EventEmitter {
     this.blockTracker.on('rawBlock', this.pendingTxTracker.checkForTxInBlock.bind(this.pendingTxTracker))
     // this is a little messy but until ethstore has been either
     // removed or redone this is to guard against the race condition
-    // where ethStore hasent been populated by the results yet
+    // where accountTracker hasent been populated by the results yet
     this.blockTracker.once('latest', () => {
       this.blockTracker.on('latest', this.pendingTxTracker.resubmitPendingTxs.bind(this.pendingTxTracker))
     })

app/scripts/lib/account-tracker.js

@@ -1,4 +1,4 @@
-/* Ethereum Store
+/* Account Tracker
  *
  * This module is responsible for tracking any number of accounts
  * and caching their current balances & transaction counts.

app/scripts/metamask-controller.js

@@ -4,7 +4,7 @@ const promiseToCallback = require('promise-to-callback')
 const pipe = require('pump')
 const Dnode = require('dnode')
 const ObservableStore = require('obs-store')
-const EthStore = require('./lib/eth-store')
+const AccountTracker = require('./lib/account-tracker')
 const EthQuery = require('eth-query')
 const streamIntoProvider = require('web3-stream-provider/handler')
 const setupMultiplex = require('./lib/stream-utils.js').setupMultiplex
@@ -81,19 +81,25 @@ module.exports = class MetamaskController extends EventEmitter {
 
     // eth data query tools
     this.ethQuery = new EthQuery(this.provider)
-    this.ethStore = new EthStore({
-      provider: this.provider,
-      blockTracker: this.provider,
-    })
 
     // key mgmt
     this.keyringController = new KeyringController({
       initState: initState.KeyringController,
-      ethStore: this.ethStore,
+      accountTracker: this.accountTracker,
       getNetwork: this.networkController.getNetworkState.bind(this.networkController),
     })
+
+    // account tracker watches balances, nonces, and any code at their address.
+    this.accountTracker = new AccountTracker({
+      provider: this.provider,
+      blockTracker: this.provider,
+    })
     this.keyringController.on('newAccount', (address) => {
       this.preferencesController.setSelectedAddress(address)
+      this.accountTracker.addAccount(address)
+    })
+    this.keyringController.on('removedAccount', (address) => {
+      this.accountTracker.removeAccount(address)
     })
 
     // address book controller
@@ -112,13 +118,13 @@ module.exports = class MetamaskController extends EventEmitter {
       provider: this.provider,
       blockTracker: this.provider,
       ethQuery: this.ethQuery,
-      ethStore: this.ethStore,
+      accountTracker: this.accountTracker,
     })
     this.txController.on('newUnaprovedTx', opts.showUnapprovedTx.bind(opts))
 
     // computed balances (accounting for pending transactions)
     this.balancesController = new BalancesController({
-      ethStore: this.ethStore,
+      accountTracker: this.accountTracker,
       txController: this.txController,
     })
     this.networkController.on('networkDidChange', () => {
@@ -177,7 +183,7 @@ module.exports = class MetamaskController extends EventEmitter {
 
     // manual mem state subscriptions
     this.networkController.store.subscribe(this.sendUpdate.bind(this))
-    this.ethStore.subscribe(this.sendUpdate.bind(this))
+    this.accountTracker.subscribe(this.sendUpdate.bind(this))
     this.txController.memStore.subscribe(this.sendUpdate.bind(this))
     this.balancesController.store.subscribe(this.sendUpdate.bind(this))
     this.messageManager.memStore.subscribe(this.sendUpdate.bind(this))
@@ -260,7 +266,7 @@ module.exports = class MetamaskController extends EventEmitter {
         isInitialized,
       },
       this.networkController.store.getState(),
-      this.ethStore.getState(),
+      this.accountTracker.getState(),
       this.txController.memStore.getState(),
       this.messageManager.memStore.getState(),
       this.personalMessageManager.memStore.getState(),