Enable ARC for //ios/web_view/internal/translate/*.m.

ios/web_view/internal/translate/web_view_translate_client.h

Index: ios/web_view/internal/translate/web_view_translate_client.h
diff --git a/ios/web_view/internal/translate/web_view_translate_client.h b/ios/web_view/internal/translate/web_view_translate_client.h
index ea806960bc5fc5631f7f33cd5911b0a93b53bd5a..8edb8cdc81853887f5420d8914ffab114026154d 100644
--- a/ios/web_view/internal/translate/web_view_translate_client.h
+++ b/ios/web_view/internal/translate/web_view_translate_client.h
@@ -37,7 +37,7 @@ class WebViewTranslateClient
  public:
   // Sets the delegate passed by the embedder.
   // |delegate| is assumed to outlive this WebViewTranslateClient.
-  void set_translate_delegate(id<CWVTranslateDelegate> delegate) {
+  void set_translate_delegate(__weak id<CWVTranslateDelegate> delegate) {
     delegate_ = delegate;
   }
 
@@ -72,7 +72,7 @@ class WebViewTranslateClient
   translate::IOSTranslateDriver translate_driver_;
 
   // Delegate provided by the embedder.
-  id<CWVTranslateDelegate> delegate_;  // Weak.
+  __weak id<CWVTranslateDelegate> delegate_;

[michaeldo, 2017/03/21 16:29:18]

Please use base::WeakNSProtocol<id<CWVTranslateDelegate>> instead of __weak.
(Note that you will need to import the delegate header and remove the @protocol
from above to avoid a cryptic error.)

[Hiroshi Ichikawa, 2017/03/22 01:32:15]

Done. Just curious, what is advantage of using WeakNSProtocol instead of __weak?

[michaeldo, 2017/03/22 02:13:46]

Good question, I don't have all the details, but it certainly plays nice with
C++ and has some other guarantees like has unittests to ensure it is nil if
never set. It is modeled after scoped_nsobject which can be used to scope an
Obj-C instance even within a C++ method body. These helpers also predate ARC
adoption where a scoped obj-C obj meant you didn't need to manually release it.

 
   DISALLOW_COPY_AND_ASSIGN(WebViewTranslateClient);
 };