Rename componentDidUnmount to componentWillUnmount

src/components/App.js

@@ -24,7 +24,7 @@ export default class App extends React.Component {
     SupportStore.listen(this._onChange)
   }
 
-  componentDidUnmount() {
+  componentWillUnmount() {
     SupportStore.unlisten(this._onChange)
   }
 

src/components/ChromeNotice.js

@@ -24,7 +24,7 @@ export default class ChromeNotice extends React.Component {
     SupportStore.listen(this._onChange)
   }
 
-  componentDidUnmount() {
+  componentWillUnmount() {
     DownloadStore.unlisten(this._onChange)
     SupportStore.unlisten(this._onChange)
   }

src/components/DownloadPage.js

@@ -23,7 +23,7 @@ export default class DownloadPage extends React.Component {
     DownloadStore.listen(this._onChange)
   }
 
-  componentDidUnmount() {
+  componentWillUnmount() {
     DownloadStore.unlisten(this._onChange)
   }
 

src/components/ErrorPage.js

@@ -17,7 +17,7 @@ export default class ErrorPage extends React.Component {
     ErrorStore.listen(this._onChange)
   }
 
-  componentDidUnmount() {
+  componentWillUnmount() {
     ErrorStore.unlisten(this._onChange)
   }
 

src/components/UploadPage.js

@@ -22,7 +22,7 @@ export default class UploadPage extends React.Component {
     UploadStore.listen(this._onChange)
   }
 
-  componentDidUnmount() {
+  componentWillUnmount() {
     UploadStore.unlisten(this._onChange)
   }