Implement delaying resource requests until privacy blacklists are ready.

chrome/browser/privacy_blacklist/blacklist_manager.cc

Index: chrome/browser/privacy_blacklist/blacklist_manager.cc
diff --git a/chrome/browser/privacy_blacklist/blacklist_manager.cc b/chrome/browser/privacy_blacklist/blacklist_manager.cc
index ca8dc0b0d01ea172f77398533b74500e5cbf6cb9..c2253ef42ab2092a95aec4019103a4a5b03a6005 100644
--- a/chrome/browser/privacy_blacklist/blacklist_manager.cc
+++ b/chrome/browser/privacy_blacklist/blacklist_manager.cc
@@ -8,6 +8,7 @@
 #include "base/string_util.h"
 #include "base/task.h"
 #include "base/thread.h"
+#include "base/utf_string_conversions.h"
 #include "chrome/browser/privacy_blacklist/blacklist.h"
 #include "chrome/browser/privacy_blacklist/blacklist_io.h"
 #include "chrome/browser/profile.h"
@@ -89,6 +90,14 @@ void BlacklistManager::CompileBlacklist() {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
   DCHECK(path_provider_->AreBlacklistPathsReady());
 
+  // The compiled blacklist is going to change. Make sure our clients don't use
+  // the old one and wait for the update instead by indicating that the compiled
+  // blacklist is not ready.
+  ChromeThread::PostTask(ChromeThread::IO, FROM_HERE,
+      NewRunnableMethod(this,
+                        &BlacklistManager::ResetPublishedCompiledBlacklist));
+
+  // Schedule actual compilation on the background thread.
   ChromeThread::PostTask(ChromeThread::FILE, FROM_HERE,
       NewRunnableMethod(this, &BlacklistManager::DoCompileBlacklist,
                         path_provider_->GetPersistentBlacklistPaths()));
@@ -98,22 +107,28 @@ void BlacklistManager::DoCompileBlacklist(
     const std::vector<FilePath>& source_blacklists) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::FILE));
 
-  bool success = true;
   Blacklist blacklist;
   std::string error_string;
+  std::vector<string16> errors;
   for (std::vector<FilePath>::const_iterator i = source_blacklists.begin();
        i != source_blacklists.end(); ++i) {
+    std::string error_string;
     if (!BlacklistIO::ReadText(&blacklist, *i, &error_string)) {
-      success = false;
-      break;
+      string16 path = WideToUTF16(i->ToWStringHack());
+      errors.push_back(path + ASCIIToUTF16(": " + error_string));
     }
   }
 
-  // Only overwrite the current compiled blacklist if we read all source
-  // files successfully.
-  if (success)
-    success = BlacklistIO::WriteBinary(&blacklist, compiled_blacklist_path_);
+  if (!errors.empty()) {
+    ChromeThread::PostTask(ChromeThread::UI, FROM_HERE,
+        NewRunnableMethod(this,
+                          &BlacklistManager::OnBlacklistCompilationReadErrors,
+                          errors));
+  }
 
+  // Write the new compiled blacklist based on the data we could read
+  // successfully.
+  bool success = BlacklistIO::WriteBinary(&blacklist, compiled_blacklist_path_);
   ChromeThread::PostTask(ChromeThread::UI, FROM_HERE,
       NewRunnableMethod(this, &BlacklistManager::OnBlacklistCompilationFinished,
                         success));
@@ -133,6 +148,21 @@ void BlacklistManager::OnBlacklistCompilationFinished(bool success) {
   }
 }
 
+void BlacklistManager::OnBlacklistCompilationReadErrors(
+    const std::vector<string16>& errors) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
+
+  string16 error_message(ASCIIToUTF16("Blacklist compilation failed.\n"));
+  for (std::vector<string16>::const_iterator i = errors.begin();
+       i != errors.end(); ++i) {
+    error_message += *i + ASCIIToUTF16("\n");
+  }
+  NotificationService::current()->Notify(
+      NotificationType::BLACKLIST_MANAGER_ERROR,
+      Source<Profile>(profile_),
+      Details<string16>(&error_message));
+}
+
 void BlacklistManager::ReadBlacklist() {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::UI));
   DCHECK(path_provider_->AreBlacklistPathsReady());
@@ -197,3 +227,8 @@ void BlacklistManager::OnBlacklistReadFinished(bool success) {
   }
   first_read_finished_ = true;
 }
+
+void BlacklistManager::ResetPublishedCompiledBlacklist() {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
+  compiled_blacklist_.reset();
+}