Extensions: Clarify ManifestHandler interface expectations.

extensions/common/manifest_handler.h

Index: extensions/common/manifest_handler.h
diff --git a/extensions/common/manifest_handler.h b/extensions/common/manifest_handler.h
index d1cf4648925149d133d86cb8878edfb417364708..2b741f09b55df578399b0601f85c96628b7a90e7 100644
--- a/extensions/common/manifest_handler.h
+++ b/extensions/common/manifest_handler.h
@@ -29,11 +29,13 @@ class ManifestHandler {
   // Attempts to parse the extension's manifest.
   // Returns true on success or false on failure; if false, |error| will
   // be set to a failure message.
+  // This should not do any IO.

[lazyboy, 2017/04/26 22:06:53]

nit:
// This does not require any IO operations.

[karandeepb, 2017/04/26 22:20:00]

Done. I was directing comments to the "implementors" of the interface.

   virtual bool Parse(Extension* extension, base::string16* error) = 0;
 
   // Validate that files associated with this manifest key exist.
   // Validation takes place after parsing. May also append a series of
-  // warning messages to |warnings|.
+  // warning messages to |warnings|. It is guaranteed that this is called on a

[lazyboy, 2017/04/26 22:06:53]

nit: It is not guaranteed, but the caller should guarantee that.
// This may require IO operations.
should be enough to give the hint.

[karandeepb, 2017/04/26 22:20:00]

Done.

+  // thread which can make IO calls.
   //
   // Otherwise, returns false, and a description of the error is
   // returned in |error|.