Do not attempt to apply app sync updates to extensions with matching ID, or vice versa.

chrome/browser/extensions/extension_service_unittest.cc

Index: chrome/browser/extensions/extension_service_unittest.cc
diff --git a/chrome/browser/extensions/extension_service_unittest.cc b/chrome/browser/extensions/extension_service_unittest.cc
index 484d0797b2198e997db0fb1fcbf4923af1e1c454..8180f964070e31f3f9508065f67990be49e4aa55 100644
--- a/chrome/browser/extensions/extension_service_unittest.cc
+++ b/chrome/browser/extensions/extension_service_unittest.cc
@@ -3540,6 +3540,29 @@ TEST_F(ExtensionServiceTest, ProcessSyncDataUninstall) {
   service_->ProcessSyncData(extension_sync_data, &AllExtensions);
 }
 
+TEST_F(ExtensionServiceTest, ProcessSyncDataWrongType) {
+  InitializeEmptyExtensionService();
+
+  ExtensionSyncData extension_sync_data;
+  extension_sync_data.id = good_crx;
+  extension_sync_data.uninstalled = true;
+
+  // Install the extension.
+  FilePath extension_path = data_dir_.AppendASCII("good.crx");
+  InstallCrx(extension_path, true);
+  EXPECT_TRUE(service_->GetExtensionById(good_crx, true));
+
+  // Should do nothing
+  service_->ProcessSyncData(extension_sync_data, &ThemesOnly);
+  EXPECT_TRUE(service_->GetExtensionById(good_crx, true));
+
+  extension_sync_data.uninstalled = false;
+  extension_sync_data.enabled = false;
+
+  // Should again do nothing.
+  service_->ProcessSyncData(extension_sync_data, &ThemesOnly);
+  EXPECT_TRUE(service_->GetExtensionById(good_crx, false));
+}
 
 TEST_F(ExtensionServiceTest, ProcessSyncDataSettings) {
   InitializeEmptyExtensionService();