Small modifications to safebrowsing code to make it simpler to add the extension

chrome/browser/safe_browsing/download_protection_service.cc

Index: chrome/browser/safe_browsing/download_protection_service.cc
diff --git a/chrome/browser/safe_browsing/download_protection_service.cc b/chrome/browser/safe_browsing/download_protection_service.cc
index bcd1643e02abb684895a3c0e7a49a5af8ee4f53f..0486e881ab856dac70203058e4ffa114e086d222 100644
--- a/chrome/browser/safe_browsing/download_protection_service.cc
+++ b/chrome/browser/safe_browsing/download_protection_service.cc
@@ -298,12 +298,13 @@ class DownloadUrlSBClient : public DownloadSBClient {
       : DownloadSBClient(info, callback, ui_manager,
                          DOWNLOAD_URL_CHECKS_TOTAL,
                          DOWNLOAD_URL_CHECKS_MALWARE),
-        database_manager_(database_manager) { }
+        database_manager_(database_manager) {
+    CHECK(database_manager_);

[Scott Hess - ex-Googler, 2013/01/11 23:44:05]

Are you certain?  The code in DownloadProtectionService clearly expects that
NULL database_manager_ is a possibility.  It would be NULL if FULL_SAFE_BROWSING
were not defined.  AFAICT, that applies to iOS and Android, but I don't know
whether in those cases the code would never arrive here, or if the short-circuit
in StartCheck() is expected to take care of it.

[not at google - send to devlin, 2013/01/14 23:00:55]

Yeah, don't know why I made this change.

+  }
 
   virtual void StartCheck() OVERRIDE {
     DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-    if (!database_manager_ || database_manager_->CheckDownloadUrl(
-            info_.download_url_chain, this)) {
+    if (database_manager_->CheckDownloadUrl(info_.download_url_chain, this)) {
       CheckDone(SB_THREAT_TYPE_SAFE);
     } else {
       AddRef();  // SafeBrowsingService takes a pointer not a scoped_refptr.