[iOS][Credential-Provider] Create directory if needed.

Bug: 1045457
Change-Id: I7bee2b914485e062bdffbbd7bf4e7f0ab345f015
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2135697
Commit-Queue: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Commit-Queue: David Jean <djean@chromium.org>
Auto-Submit: Javier Ernesto Flores Robles <javierrobles@chromium.org>
Reviewed-by: David Jean <djean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756632}

ios/chrome/common/credential_provider/archivable_credential_store.mm

@@ -32,6 +32,9 @@
 - (instancetype)initWithFileURL:(NSURL*)fileURL {
   self = [super init];
   if (self) {
+    if (fileURL) {
+      DCHECK(fileURL.isFileURL) << "URL must be a file URL.";
+    }
     _fileURL = fileURL;
     _workingQueue = dispatch_queue_create(nullptr, DISPATCH_QUEUE_CONCURRENT);
   }
@@ -89,6 +92,17 @@
       return;
     }
 
+    [[NSFileManager defaultManager]
+               createDirectoryAtURL:self.fileURL.URLByDeletingLastPathComponent
+        withIntermediateDirectories:YES
+                         attributes:nil
+                              error:&error];
+
+    if (error) {
+      completion(error);
+      return;
+    }
+
     [data writeToURL:self.fileURL options:NSDataWritingAtomic error:&error];
     DCHECK(!error) << error.debugDescription.UTF8String;
     completion(error);

ios/chrome/common/credential_provider/archivable_credential_store_unittest.mm

@@ -131,4 +131,29 @@ TEST_F(ArchivableCredentialStoreTest, persist) {
   EXPECT_TRUE(
       [credential isEqual:freshCredentialStore.credentials.firstObject]);
 }
+
+// Tests that ArchivableCredentialStore can save in a folder that doesn't exist.
+TEST_F(ArchivableCredentialStoreTest, createFolder) {
+  NSURL* deepFolderURL = [testStorageFileURL()
+      URLByAppendingPathComponent:@"a/deep/path/component"];
+  ArchivableCredentialStore* credentialStore =
+      [[ArchivableCredentialStore alloc] initWithFileURL:deepFolderURL];
+  EXPECT_TRUE(credentialStore);
+
+  ArchivableCredential* credential = TestCredential();
+  [credentialStore addCredential:credential];
+  EXPECT_EQ(1u, credentialStore.credentials.count);
+
+  __block BOOL blockWaitCompleted = false;
+  [credentialStore saveDataWithCompletion:^(NSError* error) {
+    EXPECT_FALSE(error);
+    blockWaitCompleted = true;
+  }];
+  EXPECT_TRUE(WaitUntilConditionOrTimeout(kWaitForFileOperationTimeout, ^bool {
+    return blockWaitCompleted;
+  }));
+  NSError* error = nil;
+  [deepFolderURL checkResourceIsReachableAndReturnError:&error];
+  EXPECT_FALSE(error);
+}
 }