Implement the ability to obliterate a storage partition from disk.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index 228e4eefb5a534f7cd5a91f543de958f857e3c49..7613757d56189d4ae82431ef021059b77acac143 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -290,6 +290,24 @@ class CONTENT_EXPORT ContentBrowserClient {
       std::string* partition_name,
       bool* in_memory);
 
+  // Similar to GetStoragePartitionConfigForSite(), but assumes it should
+  // parse |site| as if it were not in the default StoragePartition.
+  //
+  // If the embedder modifies the configuration of |site| so that it no
+  // longer has a non-default config there is a race where
+  // GetStoragePartitionConfigForSite() will no longer return the isolated
+  // configuration, but the embedder still needs to invoke cleanup code
+  // (such as data deleters) need to access the previous configuration.

[Charlie Reis, 2012/11/16 01:45:10]

nit: that need

[awong, 2012/11/16 02:56:10]

Function removed.

+  //
+  // This function is exposed for use by cleanup code.  This is needed because
+  // |site| has insufficient information to know whether or not it was
+  // part of the default StoragePartition.
+  virtual void ParseNonDefaultStoragePartitionConfig(

[Charlie Reis, 2012/11/16 01:45:10]

This is too complex to expose as its own function in the public API.  It's very
hard to understand how these two functions differ.

Another proposal: add something like a |might_be_default| parameter to
GetStoragePartitionConfigForSite.  If it's true, we behave as before.  If it's
false, we behave like your ParseNonDefaultStoragePartitionConfig.  It's clearer
to understand how it affects the outcome, and it seems to fit into your code
without too much effort.  Thoughts?

[awong, 2012/11/16 02:56:10]

Went with your solution.

+      const GURL& site,
+      std::string* partition_domain,
+      std::string* partition_name,
+      bool* in_memory);
+
   // Create and return a new quota permission context.
   virtual QuotaPermissionContext* CreateQuotaPermissionContext();