diff --git a/client/crash_report_database_mac.mm b/client/crash_report_database_mac.mm
index ffa7b2b6..4e25f006 100644
--- a/client/crash_report_database_mac.mm
+++ b/client/crash_report_database_mac.mm
@@ -34,6 +34,7 @@
 #include "client/settings.h"
 #include "util/file/file_io.h"
 #include "util/mac/xattr.h"
+#include "util/misc/initialization_state_dcheck.h"
 
 namespace crashpad {
 
@@ -191,6 +192,7 @@ class CrashReportDatabaseMac : public CrashReportDatabase {
 
   base::FilePath base_dir_;
   Settings settings_;
+  InitializationStateDcheck initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(CrashReportDatabaseMac);
 };
@@ -198,12 +200,15 @@ class CrashReportDatabaseMac : public CrashReportDatabase {
 CrashReportDatabaseMac::CrashReportDatabaseMac(const base::FilePath& path)
     : CrashReportDatabase(),
       base_dir_(path),
-      settings_(base_dir_.Append(kSettings)) {
+      settings_(base_dir_.Append(kSettings)),
+      initialized_() {
 }
 
 CrashReportDatabaseMac::~CrashReportDatabaseMac() {}
 
 bool CrashReportDatabaseMac::Initialize() {
+  INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
+
   // Check if the database already exists.
   if (!CreateOrEnsureDirectoryExists(base_dir_))
     return false;
@@ -219,15 +224,22 @@ bool CrashReportDatabaseMac::Initialize() {
 
   // Write an xattr as the last step, to ensure the filesystem has support for
   // them. This attribute will never be read.
-  return WriteXattrBool(base_dir_, XattrName(kXattrDatabaseInitialized), true);
+  if (!WriteXattrBool(base_dir_, XattrName(kXattrDatabaseInitialized), true))
+    return false;
+
+  INITIALIZATION_STATE_SET_VALID(initialized_);
+  return true;
 }
 
 Settings* CrashReportDatabaseMac::GetSettings() {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
   return &settings_;
 }
 
 CrashReportDatabase::OperationStatus
 CrashReportDatabaseMac::PrepareNewCrashReport(NewReport** out_report) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   uuid_t uuid_gen;
   uuid_generate(uuid_gen);
   UUID uuid(uuid_gen);
@@ -260,6 +272,8 @@ CrashReportDatabaseMac::PrepareNewCrashReport(NewReport** out_report) {
 CrashReportDatabase::OperationStatus
 CrashReportDatabaseMac::FinishedWritingCrashReport(NewReport* report,
                                                    UUID* uuid) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   // Takes ownership of the |handle| and the O_EXLOCK.
   base::ScopedFD lock(report->handle);
 
@@ -296,6 +310,8 @@ CrashReportDatabaseMac::FinishedWritingCrashReport(NewReport* report,
 
 CrashReportDatabase::OperationStatus
 CrashReportDatabaseMac::ErrorWritingCrashReport(NewReport* report) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   // Takes ownership of the |handle| and the O_EXLOCK.
   base::ScopedFD lock(report->handle);
 
@@ -315,6 +331,8 @@ CrashReportDatabaseMac::ErrorWritingCrashReport(NewReport* report) {
 CrashReportDatabase::OperationStatus
 CrashReportDatabaseMac::LookUpCrashReport(const UUID& uuid,
                                           CrashReportDatabase::Report* report) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   base::FilePath path = LocateCrashReport(uuid);
   if (path.empty())
     return kReportNotFound;
@@ -334,18 +352,24 @@ CrashReportDatabaseMac::LookUpCrashReport(const UUID& uuid,
 CrashReportDatabase::OperationStatus
 CrashReportDatabaseMac::GetPendingReports(
     std::vector<CrashReportDatabase::Report>* reports) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   return ReportsInDirectory(base_dir_.Append(kUploadPendingDirectory), reports);
 }
 
 CrashReportDatabase::OperationStatus
 CrashReportDatabaseMac::GetCompletedReports(
     std::vector<CrashReportDatabase::Report>* reports) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   return ReportsInDirectory(base_dir_.Append(kCompletedDirectory), reports);
 }
 
 CrashReportDatabase::OperationStatus
 CrashReportDatabaseMac::GetReportForUploading(const UUID& uuid,
                                               const Report** report) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   base::FilePath report_path = LocateCrashReport(uuid);
   if (report_path.empty())
     return kReportNotFound;
@@ -369,6 +393,8 @@ CrashReportDatabase::OperationStatus
 CrashReportDatabaseMac::RecordUploadAttempt(const Report* report,
                                             bool successful,
                                             const std::string& id) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   DCHECK(report);
   DCHECK(successful || id.empty());
 
@@ -425,6 +451,8 @@ CrashReportDatabaseMac::RecordUploadAttempt(const Report* report,
 
 CrashReportDatabase::OperationStatus CrashReportDatabaseMac::SkipReportUpload(
     const UUID& uuid) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   base::FilePath report_path = LocateCrashReport(uuid);
   if (report_path.empty())
     return kReportNotFound;
diff --git a/client/crash_report_database_win.cc b/client/crash_report_database_win.cc
index 8f0a3c52..b7c97d6c 100644
--- a/client/crash_report_database_win.cc
+++ b/client/crash_report_database_win.cc
@@ -24,6 +24,7 @@
 #include "base/strings/string16.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
+#include "util/misc/initialization_state_dcheck.h"
 
 namespace crashpad {
 
@@ -543,18 +544,21 @@ class CrashReportDatabaseWin : public CrashReportDatabase {
   scoped_ptr<Metadata> AcquireMetadata();
 
   base::FilePath base_dir_;
+  InitializationStateDcheck initialized_;
 
   DISALLOW_COPY_AND_ASSIGN(CrashReportDatabaseWin);
 };
 
 CrashReportDatabaseWin::CrashReportDatabaseWin(const base::FilePath& path)
-    : CrashReportDatabase(), base_dir_(path) {
+    : CrashReportDatabase(), base_dir_(path), initialized_() {
 }
 
 CrashReportDatabaseWin::~CrashReportDatabaseWin() {
 }
 
 bool CrashReportDatabaseWin::Initialize() {
+  INITIALIZATION_STATE_SET_INITIALIZING(initialized_);
+
   // Ensure the database and report subdirectories exist.
   if (!CreateDirectoryIfNecessary(base_dir_) ||
       !CreateDirectoryIfNecessary(base_dir_.Append(kReportsDirectory)))
@@ -563,10 +567,13 @@ bool CrashReportDatabaseWin::Initialize() {
   // TODO(scottmg): When are completed reports pruned from disk? Delete here or
   // maybe on AcquireMetadata().
 
+  INITIALIZATION_STATE_SET_VALID(initialized_);
   return true;
 }
 
 Settings* CrashReportDatabaseWin::GetSettings() {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   // Port to Win https://code.google.com/p/crashpad/issues/detail?id=13.
   NOTREACHED();
   return nullptr;
@@ -574,6 +581,8 @@ Settings* CrashReportDatabaseWin::GetSettings() {
 
 OperationStatus CrashReportDatabaseWin::PrepareNewCrashReport(
     NewReport** report) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   ::UUID system_uuid;
   if (UuidCreate(&system_uuid) != RPC_S_OK)
     return kFileSystemError;
@@ -599,6 +608,8 @@ OperationStatus CrashReportDatabaseWin::PrepareNewCrashReport(
 OperationStatus CrashReportDatabaseWin::FinishedWritingCrashReport(
     NewReport* report,
     UUID* uuid) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   // Take ownership of the report, and cast to our private version with UUID.
   scoped_ptr<NewReportDisk> scoped_report(static_cast<NewReportDisk*>(report));
   // Take ownership of the file handle.
@@ -617,6 +628,8 @@ OperationStatus CrashReportDatabaseWin::FinishedWritingCrashReport(
 
 OperationStatus CrashReportDatabaseWin::ErrorWritingCrashReport(
     NewReport* report) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   // Take ownership of the report, and cast to our private version with UUID.
   scoped_ptr<NewReportDisk> scoped_report(static_cast<NewReportDisk*>(report));
 
@@ -635,6 +648,8 @@ OperationStatus CrashReportDatabaseWin::ErrorWritingCrashReport(
 
 OperationStatus CrashReportDatabaseWin::LookUpCrashReport(const UUID& uuid,
                                                           Report* report) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   scoped_ptr<Metadata> metadata(AcquireMetadata());
   if (!metadata)
     return kDatabaseError;
@@ -648,6 +663,8 @@ OperationStatus CrashReportDatabaseWin::LookUpCrashReport(const UUID& uuid,
 
 OperationStatus CrashReportDatabaseWin::GetPendingReports(
     std::vector<Report>* reports) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   scoped_ptr<Metadata> metadata(AcquireMetadata());
   return metadata ? metadata->FindReports(ReportState::kPending, reports)
                   : kDatabaseError;
@@ -655,6 +672,8 @@ OperationStatus CrashReportDatabaseWin::GetPendingReports(
 
 OperationStatus CrashReportDatabaseWin::GetCompletedReports(
     std::vector<Report>* reports) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   scoped_ptr<Metadata> metadata(AcquireMetadata());
   return metadata ? metadata->FindReports(ReportState::kCompleted, reports)
                   : kDatabaseError;
@@ -663,6 +682,8 @@ OperationStatus CrashReportDatabaseWin::GetCompletedReports(
 OperationStatus CrashReportDatabaseWin::GetReportForUploading(
     const UUID& uuid,
     const Report** report) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   scoped_ptr<Metadata> metadata(AcquireMetadata());
   if (!metadata)
     return kDatabaseError;
@@ -692,6 +713,8 @@ OperationStatus CrashReportDatabaseWin::RecordUploadAttempt(
     const Report* report,
     bool successful,
     const std::string& id) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   // Take ownership, allocated in GetReportForUploading.
   scoped_ptr<const Report> upload_report(report);
   scoped_ptr<Metadata> metadata(AcquireMetadata());
@@ -716,6 +739,8 @@ OperationStatus CrashReportDatabaseWin::RecordUploadAttempt(
 }
 
 OperationStatus CrashReportDatabaseWin::SkipReportUpload(const UUID& uuid) {
+  INITIALIZATION_STATE_DCHECK_VALID(initialized_);
+
   scoped_ptr<Metadata> metadata(AcquireMetadata());
   if (!metadata)
     return kDatabaseError;