Use SyncMessageFilter to Send() ipc messages from background threads.

content/common/web_database_observer_impl.cc

-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/common/web_database_observer_impl.h"
 
 #include "base/metrics/histogram.h"
 #include "base/string16.h"
 #include "content/common/database_messages.h"
 #include "third_party/sqlite/sqlite3.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebDatabase.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebString.h"
 
+#include "base/rand_util.h"
+
 using WebKit::WebDatabase;
 
 namespace {
 
 const int kResultHistogramSize = 50;
 const int kCallsiteHistogramSize = 10;
 
 int DetermineHistogramResult(int websql_error, int sqlite_error) {
   // If we have a sqlite error, log it after trimming the extended bits.
   // There are 26 possible values, but we leave room for some new ones.
@@ skipping 30 matching lines @@
       if (result) { \
         UMA_HISTOGRAM_ENUMERATION("websql.Async." name ".ErrorSite", \
                                   callsite, kCallsiteHistogramSize); \
       } \
     } \
   } while (0)
 
 }  // namespace
 
 WebDatabaseObserverImpl::WebDatabaseObserverImpl(
-    IPC::Message::Sender* sender)
+    IPC::SyncMessageFilter* sender)
     : sender_(sender),
       open_connections_(new webkit_database::DatabaseConnectionsWrapper) {
 }
 
 WebDatabaseObserverImpl::~WebDatabaseObserverImpl() {
 }
 
 void WebDatabaseObserverImpl::databaseOpened(
     const WebDatabase& database) {
   string16 origin_identifier = database.securityOrigin().databaseIdentifier();
@@ skipping 71 matching lines @@
   }
   HandleSqliteError(database, sqlite_error);
 }
 
 void WebDatabaseObserverImpl::WaitForAllDatabasesToClose() {
   open_connections_->WaitForAllDatabasesToClose();
 }
 
 void WebDatabaseObserverImpl::HandleSqliteError(
     const WebDatabase& database, int error) {
+  // JUNK TO INDUCE ERRORS
+  int rand = base::RandInt(0, 10000);
+  if (rand < 5)
+    error = SQLITE_CORRUPT;
+  // JUNK TO INDUCE ERRORS

[michaeln, 2012/03/06 00:39:18]

oh... nevermind this JUNK and the base/rand_util include, it's unrelated and not
part of the intended CL  (this should screw up my tryjobs pretty good:)

+
   // We filter out errors which the backend doesn't act on to avoid
   // a unnecessary ipc traffic, this method can get called at a fairly
   // high frequency (per-sqlstatement).
   if (error == SQLITE_CORRUPT || error == SQLITE_NOTADB) {
     sender_->Send(new DatabaseHostMsg_HandleSqliteError(
         database.securityOrigin().databaseIdentifier(),
         database.name(),
         error));
   }
 }