Get rid of PrefService::GetMutableDictionary/GetMutableList

BUG=77914
TEST=none, trybots remain green

Review URL: http://codereview.chromium.org/6779001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@79976 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 28 insertions, 24 deletions

diff --git a/chrome/browser/background_contents_service.cc b/chrome/browser/background_contents_service.cc
index fd88660..4c63bdc 100644
--- a/chrome/browser/background_contents_service.cc
+++ b/chrome/browser/background_contents_service.cc
@@ -11,6 +11,7 @@
 #include "base/values.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
@@ -236,8 +237,8 @@ void BackgroundContentsService::RegisterBackgroundContents(
   // already an entry for this application, no need to do anything.
   // TODO(atwilson): Verify that this is the desired behavior based on developer
   // feedback (http://crbug.com/47118).
-  DictionaryValue* pref = prefs_->GetMutableDictionary(
-      prefs::kRegisteredBackgroundContents);
+  DictionaryPrefUpdate update(prefs_, prefs::kRegisteredBackgroundContents);
+  DictionaryValue* pref = update.Get();
   const string16& appid = GetParentApplicationId(background_contents);
   DictionaryValue* current;
   if (pref->GetDictionaryWithoutPathExpansion(UTF16ToUTF8(appid), &current))
@@ -257,9 +258,8 @@ void BackgroundContentsService::UnregisterBackgroundContents(
     return;
   DCHECK(IsTracked(background_contents));
   const string16 appid = GetParentApplicationId(background_contents);
-  DictionaryValue* pref = prefs_->GetMutableDictionary(
-      prefs::kRegisteredBackgroundContents);
-  pref->RemoveWithoutPathExpansion(UTF16ToUTF8(appid), NULL);
+  DictionaryPrefUpdate update(prefs_, prefs::kRegisteredBackgroundContents);
+  update.Get()->RemoveWithoutPathExpansion(UTF16ToUTF8(appid), NULL);
   prefs_->ScheduleSavePersistentPrefs();
 }
 
diff --git a/chrome/browser/background_contents_service_unittest.cc b/chrome/browser/background_contents_service_unittest.cc
index 0cb1080..a4aca14 100644
--- a/chrome/browser/background_contents_service_unittest.cc
+++ b/chrome/browser/background_contents_service_unittest.cc
@@ -11,6 +11,7 @@
 #include "chrome/browser/background_contents_service.h"
 #include "chrome/browser/browser_list.h"
 #include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/browser/tab_contents/background_contents.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/testing_browser_process.h"
@@ -28,14 +29,18 @@ class BackgroundContentsServiceTest : public TestingBrowserProcessTest {
     command_line_.reset(new CommandLine(CommandLine::NO_PROGRAM));
   }
 
-  DictionaryValue* GetPrefs(Profile* profile) {
-    return profile->GetPrefs()->GetMutableDictionary(
+  const DictionaryValue* GetPrefs(Profile* profile) {
+    return profile->GetPrefs()->GetDictionary(
         prefs::kRegisteredBackgroundContents);
   }
 
+  void ClearPrefs(Profile* profile) {
+    profile->GetPrefs()->ClearPref(prefs::kRegisteredBackgroundContents);
+  }
+
   // Returns the stored pref URL for the passed app id.
   std::string GetPrefURLForApp(Profile* profile, const string16& appid) {
-    DictionaryValue* pref = GetPrefs(profile);
+    const DictionaryValue* pref = GetPrefs(profile);
     EXPECT_TRUE(pref->HasKey(UTF16ToUTF8(appid)));
     DictionaryValue* value;
     pref->GetDictionaryWithoutPathExpansion(UTF16ToUTF8(appid), &value);
@@ -120,7 +125,7 @@ TEST_F(BackgroundContentsServiceTest, BackgroundContentsCreateDestroy) {
 
 TEST_F(BackgroundContentsServiceTest, BackgroundContentsUrlAdded) {
   TestingProfile profile;
-  GetPrefs(&profile)->Clear();
+  ClearPrefs(&profile);
   BackgroundContentsService service(&profile, command_line_.get());
   GURL orig_url;
   GURL url("http://a/");
@@ -146,7 +151,7 @@ TEST_F(BackgroundContentsServiceTest, BackgroundContentsUrlAdded) {
 
 TEST_F(BackgroundContentsServiceTest, BackgroundContentsUrlAddedAndClosed) {
   TestingProfile profile;
-  GetPrefs(&profile)->Clear();
+  ClearPrefs(&profile);
   BackgroundContentsService service(&profile, command_line_.get());
   GURL url("http://a/");
   MockBackgroundContents* contents = new MockBackgroundContents(&profile);
@@ -165,7 +170,7 @@ TEST_F(BackgroundContentsServiceTest, BackgroundContentsUrlAddedAndClosed) {
 // crash) then is restarted. Should not persist URL twice.
 TEST_F(BackgroundContentsServiceTest, RestartBackgroundContents) {
   TestingProfile profile;
-  GetPrefs(&profile)->Clear();
+  ClearPrefs(&profile);
   BackgroundContentsService service(&profile, command_line_.get());
   GURL url("http://a/");
   {
@@ -196,7 +201,7 @@ TEST_F(BackgroundContentsServiceTest, RestartBackgroundContents) {
 TEST_F(BackgroundContentsServiceTest, TestApplicationIDLinkage) {
   TestingProfile profile;
   BackgroundContentsService service(&profile, command_line_.get());
-  GetPrefs(&profile)->Clear();
+  ClearPrefs(&profile);
 
   EXPECT_EQ(NULL, service.GetAppBackgroundContents(ASCIIToUTF16("appid")));
   MockBackgroundContents* contents = new MockBackgroundContents(&profile,
diff --git a/chrome/browser/background_page_tracker.cc b/chrome/browser/background_page_tracker.cc
index 5534bbe..5c52ea0 100644
--- a/chrome/browser/background_page_tracker.cc
+++ b/chrome/browser/background_page_tracker.cc
@@ -17,6 +17,7 @@
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/prefs/scoped_user_pref_update.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/common/extensions/extension.h"
@@ -84,10 +85,8 @@ void BackgroundPageTracker::AcknowledgeBackgroundPages() {
   if (!IsEnabled())
     return;
   PrefService* prefs = GetPrefService();
-  DictionaryValue* contents =
-      prefs->GetMutableDictionary(prefs::kKnownBackgroundPages);
-  if (!contents)
-    return;
+  DictionaryPrefUpdate update(prefs, prefs::kKnownBackgroundPages);
+  DictionaryValue* contents = update.Get();
   bool prefs_modified = false;
   for (DictionaryValue::key_iterator it = contents->begin_keys();
        it != contents->end_keys(); ++it) {
@@ -194,8 +193,8 @@ bool BackgroundPageTracker::UpdateExtensionList() {
   // want to automatically mark all existing extensions as acknowledged.
   bool first_launch =
       prefs->GetDictionary(prefs::kKnownBackgroundPages) == NULL;
-  DictionaryValue* contents =
-      prefs->GetMutableDictionary(prefs::kKnownBackgroundPages);
+  DictionaryPrefUpdate update(prefs, prefs::kKnownBackgroundPages);
+  DictionaryValue* contents = update.Get();
   for (DictionaryValue::key_iterator it = contents->begin_keys();
        it != contents->end_keys(); ++it) {
     // Check to make sure that the parent extension is still enabled.
@@ -266,10 +265,10 @@ bool BackgroundPageTracker::UpdateExtensionList() {
 void BackgroundPageTracker::OnBackgroundPageLoaded(const std::string& id) {
   DCHECK(IsEnabled());
   PrefService* prefs = GetPrefService();
-  DictionaryValue* contents =
-      prefs->GetMutableDictionary(prefs::kKnownBackgroundPages);
+  DictionaryPrefUpdate update(prefs, prefs::kKnownBackgroundPages);
+  DictionaryValue* contents = update.Get();
   // No need to update our list if this extension was already known.
-  if (!contents || contents->HasKey(id))
+  if (contents->HasKey(id))
     return;
 
   // Update our list with this new as-yet-unacknowledged page.
@@ -281,10 +280,10 @@ void BackgroundPageTracker::OnBackgroundPageLoaded(const std::string& id) {
 void BackgroundPageTracker::OnExtensionUnloaded(const std::string& id) {
   DCHECK(IsEnabled());
   PrefService* prefs = GetPrefService();
-  DictionaryValue* contents =
-      prefs->GetMutableDictionary(prefs::kKnownBackgroundPages);
+  DictionaryPrefUpdate update(prefs, prefs::kKnownBackgroundPages);
+  DictionaryValue* contents = update.Get();
 
-  if (!contents || !contents->HasKey(id))
+  if (!contents->HasKey(id))
     return;
 
   contents->RemoveWithoutPathExpansion(id, NULL);