[protector] Support for collapsing multiple changes into a single one.

Each collapsible change has a key (domain). Subsequent changes with the same key are collapsed into CompositeSettingsChange.


BUG=114298
TEST=functional:protector.py; browser_tests:ProtectorServiceTest.*; unit_tests:CompositeSettingsChangeTest.*


Review URL: http://codereview.chromium.org/9968007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@131773 0039d316-1c4b-4281-b951-d872f2087c98

19 files changed, 924 insertions, 50 deletions

diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 3204eb6..d6b9d60 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -1320,10 +1320,10 @@ Psst! Incognito mode <ph name="SHORTCUT_KEY">$1<ex>(Ctrl+Shift+N)</ex></ph> may
         Change to <ph name="URL">$1<ex>google.com</ex></ph>
       </message>
 
-      <message name="IDS_SETTING_CHANGE_NO_BACKUP_TITLE" desc="The title of the bubble and the wrench menu item with a generic settings change.">
+      <message name="IDS_SETTING_CHANGE_TITLE" desc="The title of the bubble and the wrench menu item with a generic settings change.">
         Attempted settings change
       </message>
-      <message name="IDS_SETTING_CHANGE_NO_BACKUP_BUBBLE_MESSAGE" desc="The text of the generic settings change notification.">
+      <message name="IDS_SETTING_CHANGE_BUBBLE_MESSAGE" desc="The text of the generic settings change notification.">
         Arrr! Something tried to commandeer your settings!
       </message>
       <message name="IDS_SETTING_CHANGE_NO_BACKUP_STARTUP_RESET_BUBBLE_MESSAGE" desc="The text of the generic settings change notification, additionally informing user that the startup settings have been reset to defaults.">
@@ -1336,6 +1336,12 @@ Psst! Incognito mode <ph name="SHORTCUT_KEY">$1<ex>(Ctrl+Shift+N)</ex></ph> may
       <message name="IDS_KEEP_SETTING" desc="The title of the button that confirms staying with the previous settings.">
         Keep my settings
       </message>
+      <message name="IDS_CHANGE_SETTING" desc="The title of the button that confirms changing to the new settings, usually described by a domain name or search engine name.">
+        Change to <ph name="NEW_SETTING_NAME">$1<ex>Awesome Site</ex></ph>
+      </message>
+      <message name="IDS_CHANGE_SETTING_NO_NAME" desc="The title of the button that confirms changing to the new settings.">
+        Change settings
+      </message>
 
       <!-- Keywords -->
       <message name="IDS_AUTOCOMPLETE_MATCH_DESCRIPTION_SEPARATOR" desc="The separator between a result in the autocomplete popup and its description.">
diff --git a/chrome/browser/protector/base_setting_change.cc b/chrome/browser/protector/base_setting_change.cc
index 805d48b..4c5ba03 100644
--- a/chrome/browser/protector/base_setting_change.cc
+++ b/chrome/browser/protector/base_setting_change.cc
@@ -3,11 +3,20 @@
 // found in the LICENSE file.
 
 #include "chrome/browser/protector/base_setting_change.h"
+#include "chrome/browser/protector/composite_settings_change.h"
 
 #include "base/logging.h"
 
 namespace protector {
 
+// static
+const size_t kDefaultSearchProviderChangeNamePriority = 100U;
+// static
+const size_t kSessionStartupChangeNamePriority = 50U;
+
+// static
+const size_t BaseSettingChange::kDefaultNamePriority = 0U;
+
 BaseSettingChange::BaseSettingChange()
     : profile_(NULL) {
 }
@@ -15,6 +24,20 @@ BaseSettingChange::BaseSettingChange()
 BaseSettingChange::~BaseSettingChange() {
 }
 
+CompositeSettingsChange* BaseSettingChange::MergeWith(
+    BaseSettingChange* other) {
+  CompositeSettingsChange* composite_change = new CompositeSettingsChange();
+  CHECK(composite_change->Init(profile_));
+  composite_change->MergeWith(this);
+  composite_change->MergeWith(other);
+  return composite_change;
+}
+
+bool BaseSettingChange::Contains(const BaseSettingChange* other) const {
+  // BaseSettingChange can only contain itself.
+  return this == other;
+}
+
 bool BaseSettingChange::Init(Profile* profile) {
   DCHECK(profile);
   profile_ = profile;
@@ -30,4 +53,17 @@ void BaseSettingChange::Discard(Browser* browser) {
 void BaseSettingChange::Timeout() {
 }
 
+BaseSettingChange::DisplayName BaseSettingChange::GetApplyDisplayName() const {
+  return DisplayName(kDefaultNamePriority, string16());
+}
+
+GURL BaseSettingChange::GetNewSettingURL() const {
+  return GURL();
+}
+
+bool BaseSettingChange::CanBeMerged() const {
+  // By default change can be collapsed if it has a non-empty keyword.
+  return !GetNewSettingURL().is_empty();
+}
+
 }  // namespace protector
diff --git a/chrome/browser/protector/base_setting_change.h b/chrome/browser/protector/base_setting_change.h
index 42c52ad..05e680b 100644
--- a/chrome/browser/protector/base_setting_change.h
+++ b/chrome/browser/protector/base_setting_change.h
@@ -6,12 +6,12 @@
 #define CHROME_BROWSER_PROTECTOR_BASE_SETTING_CHANGE_H_
 #pragma once
 
-#include <string>
-#include <vector>
+#include <utility>
 
 #include "base/basictypes.h"
 #include "base/string16.h"
 #include "chrome/browser/tabs/pinned_tab_codec.h"
+#include "googleurl/src/gurl.h"
 
 class Browser;
 class Profile;
@@ -20,12 +20,34 @@ struct SessionStartupPref;
 
 namespace protector {
 
+class CompositeSettingsChange;
+
 // Base class for setting change tracked by Protector.
 class BaseSettingChange {
  public:
+  // Pair consisting of a display name representing either new or backup setting
+  // and priority for it. Priority is used for composite changes, consisting
+  // of multiple BaseSettingChange instances - the display name with the highest
+  // priority is used.
+  typedef std::pair<size_t, string16> DisplayName;
+
+  // Default priority value.
+  static const size_t kDefaultNamePriority;
+
   BaseSettingChange();
   virtual ~BaseSettingChange();
 
+  // Merges |this| with |other| and returns a CompositeSettingsChange instance.
+  // Returned instance takes ownership of |other|.
+  // Init should not be called for the returned instance.
+  // |this| may be another CompositeSettingsChange, in which case |other| is
+  // simply added to it and |this| is returned. |other| cannot be
+  // CompositeSettingsChange.
+  virtual CompositeSettingsChange* MergeWith(BaseSettingChange* other);
+
+  // Returns true if |this| is a result of merging some changes with |other|.
+  virtual bool Contains(const BaseSettingChange* other) const;
+
   // Applies initial actions to the setting if needed. Must be called before
   // any other calls are made, including text getters.
   // Returns true if initialization was successful.
@@ -66,6 +88,22 @@ class BaseSettingChange {
   // Returns text for the button to discard the change with |Discard|.
   virtual string16 GetDiscardButtonText() const = 0;
 
+  // Returns the display name and priority for the new setting. If multiple
+  // BaseSettingChange instances are merged into CompositeSettingsChange
+  // instance, the display name with the highest priority will be used for the
+  // Apply button (Discard button will have a generic caption in that case).
+  // Returns an empty string in |second| if there is no specific representation
+  // for new setting value and a generic string should be used.
+  virtual DisplayName GetApplyDisplayName() const;
+
+  // Returns a URL uniquely identifying new (to be applied) settings.
+  // ProtectorService uses this URLs to decide whether to merge a change
+  // with already existing active changes. The URL may be empty.
+  virtual GURL GetNewSettingURL() const;
+
+  // Returns true if this change can be merged with other changes.
+  virtual bool CanBeMerged() const;
+
  protected:
   // Profile instance we've been associated with by an |Init| call.
   Profile* profile() { return profile_; }
@@ -76,6 +114,10 @@ class BaseSettingChange {
   DISALLOW_COPY_AND_ASSIGN(BaseSettingChange);
 };
 
+// Display name priorities of various change types:
+extern const size_t kDefaultSearchProviderChangeNamePriority;
+extern const size_t kSessionStartupChangeNamePriority;
+
 // TODO(ivankr): CompositeSettingChange that incapsulates multiple
 // BaseSettingChange instances.
 
diff --git a/chrome/browser/protector/composite_settings_change.cc b/chrome/browser/protector/composite_settings_change.cc
new file mode 100644
index 0000000..a907047
--- /dev/null
+++ b/chrome/browser/protector/composite_settings_change.cc
@@ -0,0 +1,111 @@
+// 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 "chrome/browser/protector/composite_settings_change.h"
+
+#include "grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+
+namespace protector {
+
+
+CompositeSettingsChange::CompositeSettingsChange() {
+}
+
+CompositeSettingsChange::~CompositeSettingsChange() {
+}
+
+CompositeSettingsChange* CompositeSettingsChange::MergeWith(
+    BaseSettingChange* other) {
+  DCHECK(profile());
+  DCHECK(other);
+  changes_.push_back(other);
+  apply_names_.push(other->GetApplyDisplayName());
+  return this;
+}
+
+bool CompositeSettingsChange::Contains(const BaseSettingChange* other) const {
+  return this == other ||
+      std::find(changes_.begin(), changes_.end(), other) != changes_.end();
+}
+
+// Apart from PrefsBackupInvalidChange, which should never appear with other
+// Preferences-related changes together, the Apply/Discard logic of change
+// classes does not overlap, so it's safe to call them in any order.
+
+void CompositeSettingsChange::Apply(Browser* browser) {
+  DVLOG(1) << "Apply all changes";
+  for (size_t i = 0; i < changes_.size(); ++i)
+    changes_[i]->Apply(browser);
+}
+
+void CompositeSettingsChange::Discard(Browser* browser) {
+  DVLOG(1) << "Discard all changes";
+  for (size_t i = 0; i < changes_.size(); ++i)
+    changes_[i]->Discard(browser);
+}
+
+void CompositeSettingsChange::Timeout() {
+  DVLOG(1) << "Timeout all changes";
+  for (size_t i = 0; i < changes_.size(); ++i)
+    changes_[i]->Timeout();
+}
+
+int CompositeSettingsChange::GetBadgeIconID() const {
+  DCHECK(changes_.size());
+  // Use icons from the first change.
+  // TODO(ivankr): need something better, maybe a special icon.
+  return changes_[0]->GetBadgeIconID();
+}
+
+int CompositeSettingsChange::GetMenuItemIconID() const {
+  DCHECK(changes_.size());
+  return changes_[0]->GetMenuItemIconID();
+}
+
+int CompositeSettingsChange::GetBubbleIconID() const {
+  DCHECK(changes_.size());
+  return changes_[0]->GetBubbleIconID();
+}
+
+string16 CompositeSettingsChange::GetBubbleTitle() const {
+  return l10n_util::GetStringUTF16(IDS_SETTING_CHANGE_TITLE);
+}
+
+string16 CompositeSettingsChange::GetBubbleMessage() const {
+  // TODO(ivankr): indicate what kind of changes happened (i.e., "something
+  // tried to change your search engine, startup pages, etc.").
+  return l10n_util::GetStringUTF16(IDS_SETTING_CHANGE_BUBBLE_MESSAGE);
+}
+
+string16 CompositeSettingsChange::GetApplyButtonText() const {
+  DCHECK(apply_names_.size());
+  string16 apply_text = apply_names_.top().second;
+  return apply_text.empty() ?
+      l10n_util::GetStringUTF16(IDS_CHANGE_SETTING_NO_NAME) :
+      l10n_util::GetStringFUTF16(IDS_CHANGE_SETTING, apply_text);
+}
+
+string16 CompositeSettingsChange::GetDiscardButtonText() const {
+  return l10n_util::GetStringUTF16(IDS_KEEP_SETTING);
+}
+
+BaseSettingChange::DisplayName
+CompositeSettingsChange::GetApplyDisplayName() const {
+  // CompositeSettingsChange should never be put inside another one.
+  NOTREACHED();
+  return BaseSettingChange::GetApplyDisplayName();
+}
+
+GURL CompositeSettingsChange::GetNewSettingURL() const {
+  DCHECK(changes_.size());
+  return changes_[0]->GetNewSettingURL();
+}
+
+bool CompositeSettingsChange::CanBeMerged() const {
+  // We did that already, why not do it again.
+  return true;
+}
+
+}  // namespace protector
diff --git a/chrome/browser/protector/composite_settings_change.h b/chrome/browser/protector/composite_settings_change.h
new file mode 100644
index 0000000..727dd93
--- /dev/null
+++ b/chrome/browser/protector/composite_settings_change.h
@@ -0,0 +1,52 @@
+// 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.
+
+#ifndef CHROME_BROWSER_PROTECTOR_COMPOSITE_SETTINGS_CHANGE_H_
+#define CHROME_BROWSER_PROTECTOR_COMPOSITE_SETTINGS_CHANGE_H_
+#pragma once
+
+#include <queue>
+
+#include "base/memory/scoped_vector.h"
+#include "chrome/browser/protector/base_setting_change.h"
+
+namespace protector {
+
+// Class for tracking multiple settings changes as a single change.
+class CompositeSettingsChange : public BaseSettingChange {
+ public:
+  CompositeSettingsChange();
+  virtual ~CompositeSettingsChange();
+
+  // BaseSettingChange overrides:
+  virtual CompositeSettingsChange* MergeWith(BaseSettingChange* other) OVERRIDE;
+  virtual bool Contains(const BaseSettingChange* other) const OVERRIDE;
+  virtual void Apply(Browser* browser) OVERRIDE;
+  virtual void Discard(Browser* browser) OVERRIDE;
+  virtual void Timeout() OVERRIDE;
+  virtual int GetBadgeIconID() const OVERRIDE;
+  virtual int GetMenuItemIconID() const OVERRIDE;
+  virtual int GetBubbleIconID() const OVERRIDE;
+  virtual string16 GetBubbleTitle() const OVERRIDE;
+  virtual string16 GetBubbleMessage() const OVERRIDE;
+  virtual string16 GetApplyButtonText() const OVERRIDE;
+  virtual string16 GetDiscardButtonText() const OVERRIDE;
+  virtual DisplayName GetApplyDisplayName() const OVERRIDE;
+  virtual GURL GetNewSettingURL() const OVERRIDE;
+  virtual bool CanBeMerged() const OVERRIDE;
+
+ private:
+  // Vector with all merged changes.
+  ScopedVector<BaseSettingChange> changes_;
+
+  // Display names of merged changes, sorted by their priority. The name with
+  // the highest priority is picked.
+  std::priority_queue<DisplayName> apply_names_;
+
+  DISALLOW_COPY_AND_ASSIGN(CompositeSettingsChange);
+};
+
+}  // namespace protector
+
+#endif  // CHROME_BROWSER_PROTECTOR_COMPOSITE_SETTINGS_CHANGE_H_
diff --git a/chrome/browser/protector/composite_settings_change_unittest.cc b/chrome/browser/protector/composite_settings_change_unittest.cc
new file mode 100644
index 0000000..56ac4f7
--- /dev/null
+++ b/chrome/browser/protector/composite_settings_change_unittest.cc
@@ -0,0 +1,122 @@
+// 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 "base/utf_string_conversions.h"
+#include "chrome/browser/protector/composite_settings_change.h"
+#include "chrome/browser/protector/mock_setting_change.h"
+#include "chrome/test/base/testing_profile.h"
+#include "testing/gtest/include/gtest/gtest.h"
+#include "grit/generated_resources.h"
+#include "ui/base/l10n/l10n_util.h"
+
+using ::testing::NiceMock;
+using ::testing::Return;
+
+namespace protector {
+
+namespace {
+
+string16 kTitle1 = ASCIIToUTF16("A");
+string16 kTitle2 = ASCIIToUTF16("B");
+string16 kTitle3 = ASCIIToUTF16("C");
+
+};
+
+class CompositeSettingsChangeTest : public testing::Test {
+ protected:
+  string16 GetApplyButtonText(const string16& apply_text) {
+    return l10n_util::GetStringFUTF16(IDS_CHANGE_SETTING, apply_text);
+  }
+
+  TestingProfile profile_;
+};
+
+// Verify that MergeWith works and Apply/Discard/Timeout call same functions
+// of all merged changes.
+TEST_F(CompositeSettingsChangeTest, MergeWith) {
+  // These instances will be owned by CompositeSettingsChange.
+  MockSettingChange* change1 = new NiceMock<MockSettingChange>;
+  MockSettingChange* change2 = new NiceMock<MockSettingChange>;
+  MockSettingChange* change3 = new NiceMock<MockSettingChange>;
+
+  EXPECT_CALL(*change1, MockInit(&profile_)).WillOnce(Return(true));
+  ASSERT_TRUE(change1->Init(&profile_));
+  EXPECT_CALL(*change2, MockInit(&profile_)).WillOnce(Return(true));
+  ASSERT_TRUE(change2->Init(&profile_));
+  EXPECT_CALL(*change3, MockInit(&profile_)).WillOnce(Return(true));
+  ASSERT_TRUE(change3->Init(&profile_));
+
+  // Compose 1st and 2nd changes together.
+  scoped_ptr<CompositeSettingsChange> composite_change(
+      change1->MergeWith(change2));
+
+  EXPECT_TRUE(composite_change->Contains(change1));
+  EXPECT_TRUE(composite_change->Contains(change2));
+  EXPECT_FALSE(composite_change->Contains(change3));
+  EXPECT_TRUE(composite_change->Contains(composite_change.get()));
+
+  // Add third change.
+  EXPECT_EQ(composite_change.get(), composite_change->MergeWith(change3));
+
+  EXPECT_TRUE(composite_change->Contains(change1));
+  EXPECT_TRUE(composite_change->Contains(change2));
+  EXPECT_TRUE(composite_change->Contains(change3));
+  EXPECT_TRUE(composite_change->Contains(composite_change.get()));
+
+  // Apply/Discard/Timeout calls should be proxied to inner change instances:
+  EXPECT_CALL(*change1, Apply(NULL));
+  EXPECT_CALL(*change2, Apply(NULL));
+  EXPECT_CALL(*change3, Apply(NULL));
+  composite_change->Apply(NULL);
+
+  EXPECT_CALL(*change1, Discard(NULL));
+  EXPECT_CALL(*change2, Discard(NULL));
+  EXPECT_CALL(*change3, Discard(NULL));
+  composite_change->Discard(NULL);
+
+  EXPECT_CALL(*change1, Timeout());
+  EXPECT_CALL(*change2, Timeout());
+  EXPECT_CALL(*change3, Timeout());
+  composite_change->Timeout();
+}
+
+TEST_F(CompositeSettingsChangeTest, ApplyButtonText) {
+  // These instances will be owned by CompositeSettingsChange.
+  MockSettingChange* change1 = new NiceMock<MockSettingChange>;
+  MockSettingChange* change2 = new NiceMock<MockSettingChange>;
+  MockSettingChange* change3 = new NiceMock<MockSettingChange>;
+
+  EXPECT_CALL(*change1, MockInit(&profile_)).WillOnce(Return(true));
+  ASSERT_TRUE(change1->Init(&profile_));
+  EXPECT_CALL(*change2, MockInit(&profile_)).WillOnce(Return(true));
+  ASSERT_TRUE(change2->Init(&profile_));
+  EXPECT_CALL(*change3, MockInit(&profile_)).WillOnce(Return(true));
+  ASSERT_TRUE(change3->Init(&profile_));
+
+  // |change1| has higher priority.
+  EXPECT_CALL(*change1, GetApplyDisplayName()).WillOnce(
+      Return(BaseSettingChange::DisplayName(10, kTitle1)));
+  EXPECT_CALL(*change2, GetApplyDisplayName()).WillOnce(
+      Return(BaseSettingChange::DisplayName(5, kTitle2)));
+
+  scoped_ptr<CompositeSettingsChange> composite_change(
+      change1->MergeWith(change2));
+
+  EXPECT_EQ(GetApplyButtonText(kTitle1),
+            composite_change->GetApplyButtonText());
+
+  // |change3| has the highest priority now.
+  EXPECT_CALL(*change3, GetApplyDisplayName()).WillOnce(
+      Return(BaseSettingChange::DisplayName(15, kTitle3)));
+  EXPECT_EQ(composite_change.get(), composite_change->MergeWith(change3));
+
+  EXPECT_EQ(GetApplyButtonText(kTitle3),
+            composite_change->GetApplyButtonText());
+
+  GURL url1("example.com");
+  EXPECT_CALL(*change1, GetNewSettingURL()).WillOnce(Return(url1));
+  EXPECT_EQ(url1, composite_change->GetNewSettingURL());
+}
+
+}  // namespace protector
diff --git a/chrome/browser/protector/default_search_provider_change.cc b/chrome/browser/protector/default_search_provider_change.cc
index 28df6ed..774655a 100644
--- a/chrome/browser/protector/default_search_provider_change.cc
+++ b/chrome/browser/protector/default_search_provider_change.cc
@@ -97,6 +97,8 @@ class DefaultSearchProviderChange : public BaseSettingChange,
   virtual string16 GetBubbleMessage() const OVERRIDE;
   virtual string16 GetApplyButtonText() const OVERRIDE;
   virtual string16 GetDiscardButtonText() const OVERRIDE;
+  virtual DisplayName GetApplyDisplayName() const OVERRIDE;
+  virtual GURL GetNewSettingURL() const OVERRIDE;
 
  private:
   virtual ~DefaultSearchProviderChange();
@@ -322,6 +324,28 @@ string16 DefaultSearchProviderChange::GetDiscardButtonText() const {
   return l10n_util::GetStringUTF16(IDS_SELECT_SEARCH_ENGINE);
 }
 
+BaseSettingChange::DisplayName
+DefaultSearchProviderChange::GetApplyDisplayName() const {
+  if (new_search_provider_ &&
+      new_search_provider_->short_name().length() <= kMaxDisplayedNameLength) {
+    return DisplayName(kDefaultSearchProviderChangeNamePriority,
+                       new_search_provider_->short_name());
+  }
+  // Return the default empty name.
+  return BaseSettingChange::GetApplyDisplayName();
+}
+
+GURL DefaultSearchProviderChange::GetNewSettingURL() const {
+  if (is_fallback_) {
+    // Do not collide this change when fallback was made, since the message
+    // and Discard behaviour is pretty different.
+    return GURL();
+  }
+  if (!new_search_provider_)
+    return GURL();
+  return TemplateURLService::GenerateSearchURL(new_search_provider_);
+}
+
 void DefaultSearchProviderChange::OnTemplateURLServiceChanged() {
   TemplateURLService* url_service = GetTemplateURLService();
   if (url_service->GetDefaultSearchProvider() != default_search_provider_) {
diff --git a/chrome/browser/protector/default_search_provider_change_browsertest.cc b/chrome/browser/protector/default_search_provider_change_browsertest.cc
index 9e4fae8..e5a63e7 100644
--- a/chrome/browser/protector/default_search_provider_change_browsertest.cc
+++ b/chrome/browser/protector/default_search_provider_change_browsertest.cc
@@ -6,6 +6,7 @@
 #include "base/metrics/histogram.h"
 #include "base/message_loop.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/protector/base_setting_change.h"
 #include "chrome/browser/protector/histograms.h"
 #include "chrome/browser/protector/mock_protector_service.h"
 #include "chrome/browser/protector/protector_service_factory.h"
@@ -25,17 +26,25 @@ using ::testing::Invoke;
 using ::testing::NiceMock;
 using ::testing::Return;
 
+namespace protector {
+
 namespace {
 
 // Keyword names and URLs used for testing.
 const string16 example_info = ASCIIToUTF16("Example.info");
 const string16 example_info_long = ASCIIToUTF16("ExampleSearchEngine.info");
-const std::string http_example_info = "http://example.info/%s";
+const std::string http_example_info = "http://example.info/?q={searchTerms}";
+const std::string example_info_domain = "example.info";
 const string16 example_com = ASCIIToUTF16("Example.com");
 const string16 example_com_long = ASCIIToUTF16("ExampleSearchEngine.com");
-const std::string http_example_com = "http://example.com/%s";
+const std::string http_example_com = "http://example.com/?q={searchTerms}";
+const std::string example_com_domain = "example.com";
 const string16 example_net = ASCIIToUTF16("Example.net");
-const std::string http_example_net = "http://example.net/%s";
+const std::string http_example_net = "http://example.net/?q={searchTerms}";
+const std::string example_domain = "example.net";
+
+const BaseSettingChange::DisplayName kNoDisplayName(
+    BaseSettingChange::kDefaultNamePriority, string16());
 
 // Convenience function.
 TemplateURL* MakeTemplateURL(const string16& short_name,
@@ -51,9 +60,7 @@ TemplateURL* MakeTemplateURL(const string16& short_name,
   return new TemplateURL(data);
 }
 
-};
-
-namespace protector {
+}  // namespace
 
 class DefaultSearchProviderChangeTest : public InProcessBrowserTest {
  public:
@@ -176,6 +183,8 @@ IN_PROC_BROWSER_TEST_F(DefaultSearchProviderChangeTest, BackupValid) {
             change->GetApplyButtonText());
   EXPECT_EQ(GetKeepSearchButtonText(example_info),
             change->GetDiscardButtonText());
+  EXPECT_EQ(example_com_domain, change->GetNewSettingURL().host());
+  EXPECT_EQ(example_com, change->GetApplyDisplayName().second);
 
   // Discard does nothing - backup was already active.
   change->Discard(browser());
@@ -218,6 +227,8 @@ IN_PROC_BROWSER_TEST_F(DefaultSearchProviderChangeTest, BackupValidLongNames) {
     EXPECT_EQ(GetChangeSearchButtonText(example_com),
               change->GetApplyButtonText());
     EXPECT_EQ(GetKeepSearchButtonText(), change->GetDiscardButtonText());
+    EXPECT_EQ(example_com_domain, change->GetNewSettingURL().host());
+    EXPECT_EQ(example_com, change->GetApplyDisplayName().second);
   }
 
   {
@@ -235,6 +246,8 @@ IN_PROC_BROWSER_TEST_F(DefaultSearchProviderChangeTest, BackupValidLongNames) {
     EXPECT_EQ(GetChangeSearchButtonText(), change->GetApplyButtonText());
     EXPECT_EQ(GetKeepSearchButtonText(example_info),
               change->GetDiscardButtonText());
+    EXPECT_EQ(example_com_domain, change->GetNewSettingURL().host());
+    EXPECT_EQ(kNoDisplayName, change->GetApplyDisplayName());
   }
 }
 
@@ -334,6 +347,8 @@ IN_PROC_BROWSER_TEST_F(DefaultSearchProviderChangeTest,
   EXPECT_EQ(GetChangeSearchButtonText(example_com),
             change->GetApplyButtonText());
   EXPECT_EQ(GetOpenSettingsButtonText(), change->GetDiscardButtonText());
+  EXPECT_EQ(GURL(), change->GetNewSettingURL());
+  EXPECT_EQ(example_com, change->GetApplyDisplayName().second);
 
   // Verify that search engine settings are opened by Discard.
   ExpectSettingsOpened(chrome::kSearchEnginesSubPage);
@@ -377,6 +392,8 @@ IN_PROC_BROWSER_TEST_F(DefaultSearchProviderChangeTest,
   EXPECT_EQ(GetOpenSettingsButtonText(), change->GetApplyButtonText());
   EXPECT_EQ(GetKeepSearchButtonText(example_info),
             change->GetDiscardButtonText());
+  EXPECT_EQ(GURL(), change->GetNewSettingURL());
+  EXPECT_EQ(kNoDisplayName, change->GetApplyDisplayName());
 
   // Discard does nothing - backup was already active.
   change->Discard(browser());
@@ -420,6 +437,8 @@ IN_PROC_BROWSER_TEST_F(DefaultSearchProviderChangeTest,
             change->GetBubbleMessage());
   EXPECT_EQ(string16(), change->GetApplyButtonText());
   EXPECT_EQ(GetOpenSettingsButtonText(), change->GetDiscardButtonText());
+  EXPECT_EQ(GURL(), change->GetNewSettingURL());
+  EXPECT_EQ(kNoDisplayName, change->GetApplyDisplayName());
 
   // Verify that search engine settings are opened by Discard.
   ExpectSettingsOpened(chrome::kSearchEnginesSubPage);
@@ -461,6 +480,8 @@ IN_PROC_BROWSER_TEST_F(DefaultSearchProviderChangeTest,
             change->GetBubbleMessage());
   EXPECT_EQ(string16(), change->GetApplyButtonText());
   EXPECT_EQ(GetOpenSettingsButtonText(), change->GetDiscardButtonText());
+  EXPECT_EQ(GURL(), change->GetNewSettingURL());
+  EXPECT_EQ(current_url->short_name(), change->GetApplyDisplayName().second);
 
   // Verify that search engine settings are opened by Discard.
   ExpectSettingsOpened(chrome::kSearchEnginesSubPage);
@@ -525,6 +546,8 @@ IN_PROC_BROWSER_TEST_F(DefaultSearchProviderChangeTest,
   EXPECT_EQ(GetOpenSettingsButtonText(), change->GetApplyButtonText());
   EXPECT_EQ(GetKeepSearchButtonText(example_info),
             change->GetDiscardButtonText());
+  EXPECT_EQ(GURL(), change->GetNewSettingURL());
+  EXPECT_EQ(kNoDisplayName, change->GetApplyDisplayName());
 
   // Verify that search engine settings are opened by Apply.
   ExpectSettingsOpened(chrome::kSearchEnginesSubPage);
diff --git a/chrome/browser/protector/mock_setting_change.cc b/chrome/browser/protector/mock_setting_change.cc
index 53bc9f3..34581e0 100644
--- a/chrome/browser/protector/mock_setting_change.cc
+++ b/chrome/browser/protector/mock_setting_change.cc
@@ -25,6 +25,13 @@ MockSettingChange::MockSettingChange() {
       WillByDefault(Return(UTF8ToUTF16("Apply")));
   ON_CALL(*this, GetDiscardButtonText()).
       WillByDefault(Return(UTF8ToUTF16("Discard")));
+
+  ON_CALL(*this, GetApplyDisplayName()).
+      WillByDefault(Return(
+          DisplayName(kDefaultNamePriority, UTF8ToUTF16("new settings"))));
+
+  ON_CALL(*this, GetNewSettingURL()).WillByDefault(Return(GURL()));
+  ON_CALL(*this, CanBeMerged()).WillByDefault(Return(false));
 }
 
 MockSettingChange::~MockSettingChange() {
diff --git a/chrome/browser/protector/mock_setting_change.h b/chrome/browser/protector/mock_setting_change.h
index c665ced..dd66626 100644
--- a/chrome/browser/protector/mock_setting_change.h
+++ b/chrome/browser/protector/mock_setting_change.h
@@ -32,6 +32,11 @@ class MockSettingChange : public BaseSettingChange {
   MOCK_CONST_METHOD0(GetBubbleMessage, string16());
   MOCK_CONST_METHOD0(GetApplyButtonText, string16());
   MOCK_CONST_METHOD0(GetDiscardButtonText, string16());
+
+  MOCK_CONST_METHOD0(GetApplyDisplayName, DisplayName());
+
+  MOCK_CONST_METHOD0(GetNewSettingURL, GURL());
+  MOCK_CONST_METHOD0(CanBeMerged, bool());
 };
 
 }  // namespace protector
diff --git a/chrome/browser/protector/prefs_backup_invalid_change.cc b/chrome/browser/protector/prefs_backup_invalid_change.cc
index a9cb839..2d86584 100644
--- a/chrome/browser/protector/prefs_backup_invalid_change.cc
+++ b/chrome/browser/protector/prefs_backup_invalid_change.cc
@@ -40,6 +40,7 @@ class PrefsBackupInvalidChange : public BasePrefsChange {
   virtual string16 GetBubbleMessage() const OVERRIDE;
   virtual string16 GetApplyButtonText() const OVERRIDE;
   virtual string16 GetDiscardButtonText() const OVERRIDE;
+  virtual bool CanBeMerged() const OVERRIDE;
 
  private:
   virtual ~PrefsBackupInvalidChange();
@@ -100,14 +101,14 @@ int PrefsBackupInvalidChange::GetBubbleIconID() const {
 }
 
 string16 PrefsBackupInvalidChange::GetBubbleTitle() const {
-  return l10n_util::GetStringUTF16(IDS_SETTING_CHANGE_NO_BACKUP_TITLE);
+  return l10n_util::GetStringUTF16(IDS_SETTING_CHANGE_TITLE);
 }
 
 string16 PrefsBackupInvalidChange::GetBubbleMessage() const {
   return startup_pref_reset_ ?
       l10n_util::GetStringUTF16(
           IDS_SETTING_CHANGE_NO_BACKUP_STARTUP_RESET_BUBBLE_MESSAGE) :
-      l10n_util::GetStringUTF16(IDS_SETTING_CHANGE_NO_BACKUP_BUBBLE_MESSAGE);
+      l10n_util::GetStringUTF16(IDS_SETTING_CHANGE_BUBBLE_MESSAGE);
 }
 
 string16 PrefsBackupInvalidChange::GetApplyButtonText() const {
@@ -131,6 +132,10 @@ void PrefsBackupInvalidChange::ApplyDefaults(Profile* profile) {
   }
 }
 
+bool PrefsBackupInvalidChange::CanBeMerged() const {
+  return false;
+}
+
 BaseSettingChange* CreatePrefsBackupInvalidChange() {
   return new PrefsBackupInvalidChange();
 }
diff --git a/chrome/browser/protector/protector_service.cc b/chrome/browser/protector/protector_service.cc
index ce8b20a..4b790a7 100644
--- a/chrome/browser/protector/protector_service.cc
+++ b/chrome/browser/protector/protector_service.cc
@@ -5,16 +5,34 @@
 #include "chrome/browser/protector/protector_service.h"
 
 #include "base/logging.h"
+#include "chrome/browser/google/google_util.h"
 #include "chrome/browser/prefs/pref_service.h"
-#include "chrome/browser/protector/settings_change_global_error.h"
+#include "chrome/browser/protector/composite_settings_change.h"
+#include "chrome/browser/protector/keys.h"
 #include "chrome/browser/protector/protected_prefs_watcher.h"
+#include "chrome/browser/protector/settings_change_global_error.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/notification_source.h"
+#include "net/base/registry_controlled_domain.h"
 
 namespace protector {
 
+namespace {
+
+// Returns true if changes with URLs |url1| and |url2| can be merged.
+bool CanMerge(const GURL& url1, const GURL& url2) {
+  VLOG(1) << "Checking if can merge " << url1.spec() << " with " << url2.spec();
+  // All Google URLs are considered the same one.
+  if (google_util::IsGoogleHostname(url1.host()))
+    return google_util::IsGoogleHostname(url2.host());
+  // Otherwise URLs must have the same domain.
+  return net::RegistryControlledDomainService::SameDomainOrHost(url1, url2);
+}
+
+}  // namespace
+
 ProtectorService::ProtectorService(Profile* profile)
     : profile_(profile),
       has_active_change_(false) {
@@ -28,20 +46,37 @@ ProtectorService::~ProtectorService() {
 
 void ProtectorService::ShowChange(BaseSettingChange* change) {
   DCHECK(change);
-  Item new_item;
-  new_item.change.reset(change);
+
   DVLOG(1) << "Init change";
   if (!change->Init(profile_)) {
     LOG(WARNING) << "Error while initializing, dismissing change";
+    delete change;
     return;
   }
-  SettingsChangeGlobalError* error =
-      new SettingsChangeGlobalError(change, this);
-  new_item.error.reset(error);
-  items_.push_back(new_item);
-  // Do not show the bubble immediately if another one is active.
-  error->AddToProfile(profile_, !has_active_change_);
-  has_active_change_ = true;
+
+  Item* item_to_merge_with = FindItemToMergeWith(change);
+  if (item_to_merge_with) {
+    // CompositeSettingsChange takes ownership of merged changes.
+    BaseSettingChange* existing_change = item_to_merge_with->change.release();
+    CompositeSettingsChange* merged_change = existing_change->MergeWith(change);
+    item_to_merge_with->change.reset(merged_change);
+    item_to_merge_with->was_merged = true;
+    if (item_to_merge_with->error->GetBubbleView())
+      item_to_merge_with->show_when_merged = true;
+    // Remove old GlobalError instance. Later in OnRemovedFromProfile() a new
+    // GlobalError instance will be created for the composite change.
+    item_to_merge_with->error->RemoveFromProfile();
+  } else {
+    Item new_item;
+    SettingsChangeGlobalError* error =
+        new SettingsChangeGlobalError(change, this);
+    new_item.error.reset(error);
+    new_item.change.reset(change);
+    items_.push_back(new_item);
+    // Do not show the bubble immediately if another one is active.
+    error->AddToProfile(profile_, !has_active_change_);
+    has_active_change_ = true;
+  }
 }
 
 bool ProtectorService::IsShowingChange() const {
@@ -61,8 +96,8 @@ void ProtectorService::DiscardChange(BaseSettingChange* change,
 }
 
 void ProtectorService::DismissChange(BaseSettingChange* change) {
-  std::vector<Item>::iterator item =
-      std::find_if(items_.begin(), items_.end(), MatchItemByChange(change));
+  Items::iterator item = std::find_if(items_.begin(), items_.end(),
+                                      MatchItemByChange(change));
   DCHECK(item != items_.end());
   item->error->RemoveFromProfile();
 }
@@ -76,6 +111,19 @@ ProtectedPrefsWatcher* ProtectorService::GetPrefsWatcher() {
   return prefs_watcher_.get();
 }
 
+ProtectorService::Item* ProtectorService::FindItemToMergeWith(
+    const BaseSettingChange* change) {
+  if (!change->CanBeMerged())
+    return NULL;
+  GURL url = change->GetNewSettingURL();
+  for (Items::iterator item = items_.begin(); item != items_.end(); item++) {
+    if (item->change->CanBeMerged() &&
+        CanMerge(url, item->change->GetNewSettingURL()))
+      return &*item;
+  }
+  return NULL;
+}
+
 void ProtectorService::Shutdown() {
   while (IsShowingChange())
     items_[0].error->RemoveFromProfile();
@@ -101,13 +149,27 @@ void ProtectorService::OnDecisionTimeout(SettingsChangeGlobalError* error) {
 }
 
 void ProtectorService::OnRemovedFromProfile(SettingsChangeGlobalError* error) {
-  std::vector<Item>::iterator item =
-      std::find_if(items_.begin(), items_.end(), MatchItemByError(error));
+  Items::iterator item = std::find_if(items_.begin(), items_.end(),
+                                      MatchItemByError(error));
   DCHECK(item != items_.end());
+
+  if (item->was_merged) {
+    bool show_new_error = !has_active_change_ || item->show_when_merged;
+    item->was_merged = false;
+    item->show_when_merged = false;
+    // Item was merged with another change instance and error has been removed,
+    // create a new one for the composite change.
+    item->error.reset(new SettingsChangeGlobalError(item->change.get(), this));
+    item->error->AddToProfile(profile_, show_new_error);
+    has_active_change_ = true;
+    return;
+  }
+
   items_.erase(item);
 
+  // If no other change is shown and there are changes that haven't been shown
+  // yet, show the first one.
   if (!has_active_change_) {
-    // If there are changes that haven't been shown yet, show the first one.
     for (item = items_.begin(); item != items_.end(); ++item) {
       if (!item->error->HasShownBubbleView()) {
         item->error->ShowBubble();
@@ -122,7 +184,9 @@ BaseSettingChange* ProtectorService::GetLastChange() {
   return items_.empty() ? NULL : items_.back().change.get();
 }
 
-ProtectorService::Item::Item() {
+ProtectorService::Item::Item()
+    : was_merged(false),
+      show_when_merged(false) {
 }
 
 ProtectorService::Item::~Item() {
@@ -134,7 +198,7 @@ ProtectorService::MatchItemByChange::MatchItemByChange(
 
 bool ProtectorService::MatchItemByChange::operator()(
     const ProtectorService::Item& item) {
-  return other_ == item.change.get();
+  return item.change->Contains(other_);
 }
 
 ProtectorService::MatchItemByError::MatchItemByError(
diff --git a/chrome/browser/protector/protector_service.h b/chrome/browser/protector/protector_service.h
index 7d0637d..ba56448 100644
--- a/chrome/browser/protector/protector_service.h
+++ b/chrome/browser/protector/protector_service.h
@@ -71,15 +71,24 @@ class ProtectorService : public ProfileKeyedService,
  private:
   friend class ProtectorServiceTest;
 
-  // Pair of error and corresponding change instance. linked_ptr is used because
-  // Item instances are stored in a std::vector and must be copyable.
+  // Each item consists of an error and corresponding change instance.
+  // linked_ptr is used because Item instances are stored in a std::vector and
+  // must be copyable.
   struct Item {
     Item();
     ~Item();
     linked_ptr<BaseSettingChange> change;
     linked_ptr<SettingsChangeGlobalError> error;
+    // When true, this means |change| was merged with another instance and
+    // |error| is in process of being removed from GlobalErrorService.
+    bool was_merged;
+    // Meaningful only when |was_merged| is true. In that case, true means that
+    // the new merged GlobalError instance will be immediately shown.
+    bool show_when_merged;
   };
 
+  typedef std::vector<Item> Items;
+
   // Matches Item by |change| field.
   class MatchItemByChange {
    public:
@@ -102,6 +111,11 @@ class ProtectorService : public ProfileKeyedService,
     const SettingsChangeGlobalError* other_;
   };
 
+  // Returns an Item instance whose change can be merged with |change|, if any.
+  // Otherwise returns |NULL|. Provided that the merge strategy is transitive,
+  // there can be only one such instance.
+  Item* FindItemToMergeWith(const BaseSettingChange* change);
+
   // ProfileKeyedService implementation.
   virtual void Shutdown() OVERRIDE;
 
@@ -115,7 +129,7 @@ class ProtectorService : public ProfileKeyedService,
 
   // Pointers to error bubble controllers and corresponding changes in the order
   // added.
-  std::vector<Item> items_;
+  Items items_;
 
   // Profile which settings we are protecting.
   Profile* profile_;
diff --git a/chrome/browser/protector/protector_service_browsertest.cc b/chrome/browser/protector/protector_service_browsertest.cc
index 17912ff..936359f 100644
--- a/chrome/browser/protector/protector_service_browsertest.cc
+++ b/chrome/browser/protector/protector_service_browsertest.cc
@@ -34,12 +34,13 @@ class ProtectorServiceTest : public InProcessBrowserTest {
 
  protected:
   GlobalError* GetGlobalError(BaseSettingChange* change) {
-    std::vector<ProtectorService::Item>::iterator item =
-        std::find_if(protector_service_->items_.begin(),
-                     protector_service_->items_.end(),
-                     ProtectorService::MatchItemByChange(change));
-    return item == protector_service_->items_.end() ?
-        NULL : item->error.get();
+    for (ProtectorService::Items::iterator item =
+             protector_service_->items_.begin();
+         item != protector_service_->items_.end(); item++) {
+      if (item->change.get() == change)
+        return item->error.get();
+    }
+    return NULL;
   }
 
   // Checks that |protector_service_| has an error instance corresponding to
@@ -67,6 +68,7 @@ IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ChangeInitError) {
   EXPECT_FALSE(IsGlobalErrorActive(mock_change_));
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_FALSE(IsGlobalErrorActive(mock_change_));
+  EXPECT_FALSE(protector_service_->GetLastChange());
 }
 
 IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowAndDismiss) {
@@ -76,9 +78,11 @@ IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowAndDismiss) {
   protector_service_->ShowChange(mock_change_);
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
+  EXPECT_EQ(mock_change_, protector_service_->GetLastChange());
   protector_service_->DismissChange(mock_change_);
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_FALSE(IsGlobalErrorActive(mock_change_));
+  EXPECT_FALSE(protector_service_->GetLastChange());
 }
 
 IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowAndApply) {
@@ -167,16 +171,19 @@ IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowMultipleChangesAndApply) {
   protector_service_->ShowChange(mock_change_);
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
+  EXPECT_EQ(mock_change_, protector_service_->GetLastChange());
 
   // ProtectService will own this change instance as well.
   MockSettingChange* mock_change2 = new NiceMock<MockSettingChange>();
   // Show the second change.
   EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
       WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(false));
   protector_service_->ShowChange(mock_change2);
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
   EXPECT_TRUE(IsGlobalErrorActive(mock_change2));
+  EXPECT_EQ(mock_change2, protector_service_->GetLastChange());
 
   // Apply the first change, the second should still be active.
   EXPECT_CALL(*mock_change_, Apply(browser()));
@@ -184,6 +191,7 @@ IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowMultipleChangesAndApply) {
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_FALSE(IsGlobalErrorActive(mock_change_));
   EXPECT_TRUE(IsGlobalErrorActive(mock_change2));
+  EXPECT_EQ(mock_change2, protector_service_->GetLastChange());
 
   // Finally apply the second change.
   EXPECT_CALL(*mock_change2, Apply(browser()));
@@ -191,6 +199,7 @@ IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowMultipleChangesAndApply) {
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_FALSE(IsGlobalErrorActive(mock_change_));
   EXPECT_FALSE(IsGlobalErrorActive(mock_change2));
+  EXPECT_FALSE(protector_service_->GetLastChange());
 }
 
 IN_PROC_BROWSER_TEST_F(ProtectorServiceTest,
@@ -207,6 +216,7 @@ IN_PROC_BROWSER_TEST_F(ProtectorServiceTest,
   // Show the second change.
   EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
       WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(false));
   protector_service_->ShowChange(mock_change2);
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
@@ -245,6 +255,7 @@ IN_PROC_BROWSER_TEST_F(ProtectorServiceTest,
   // Show the second change.
   EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
       WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(false));
   protector_service_->ShowChange(mock_change2);
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
@@ -303,6 +314,7 @@ IN_PROC_BROWSER_TEST_F(ProtectorServiceTest,
   // Show the second change.
   EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
       WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(false));
   protector_service_->ShowChange(mock_change2);
   ui_test_utils::RunAllPendingInMessageLoop();
   EXPECT_TRUE(IsGlobalErrorActive(mock_change2));
@@ -320,6 +332,310 @@ IN_PROC_BROWSER_TEST_F(ProtectorServiceTest,
   EXPECT_FALSE(IsGlobalErrorActive(mock_change2));
 }
 
+IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowMultipleDifferentURLs) {
+  GURL url1("http://example.com/");
+  GURL url2("http://example.net/");
+
+  // Show the first change with some non-empty URL.
+  EXPECT_CALL(*mock_change_, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change_, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change_, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change_);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
+  EXPECT_EQ(mock_change_, protector_service_->GetLastChange());
+
+  // ProtectService will own this change instance as well.
+  MockSettingChange* mock_change2 = new NiceMock<MockSettingChange>();
+  // Show the second change with another non-empty URL.
+  EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, GetNewSettingURL()).WillRepeatedly(Return(url2));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change2);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // Both changes are shown separately, not composited.
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change2));
+  EXPECT_EQ(mock_change2, protector_service_->GetLastChange());
+
+  protector_service_->DismissChange(mock_change_);
+  protector_service_->DismissChange(mock_change2);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_FALSE(protector_service_->GetLastChange());
+}
+
+IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowCompositeAndDismiss) {
+  GURL url1("http://example.com/");
+
+  // Show the first change.
+  EXPECT_CALL(*mock_change_, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change_, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change_, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change_);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
+  EXPECT_EQ(mock_change_, protector_service_->GetLastChange());
+
+  // The first bubble view has been displayed.
+  GlobalError* error = GetGlobalError(mock_change_);
+  ASSERT_TRUE(error);
+  EXPECT_TRUE(error->HasShownBubbleView());
+
+  // ProtectService will own this change instance as well.
+  MockSettingChange* mock_change2 = new NiceMock<MockSettingChange>();
+  // Show the second change.
+  EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change2);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // Now ProtectorService should be showing a single composite change.
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change_));
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change2));
+
+  BaseSettingChange* composite_change = protector_service_->GetLastChange();
+  ASSERT_TRUE(composite_change);
+  EXPECT_TRUE(IsGlobalErrorActive(composite_change));
+
+  // The second (composite) bubble view has been displayed.
+  GlobalError* error2 = GetGlobalError(composite_change);
+  ASSERT_TRUE(error2);
+  EXPECT_TRUE(error2->HasShownBubbleView());
+
+  protector_service_->DismissChange(composite_change);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_FALSE(IsGlobalErrorActive(composite_change));
+  EXPECT_FALSE(protector_service_->GetLastChange());
+
+  // Show the third change.
+  MockSettingChange* mock_change3 = new NiceMock<MockSettingChange>();
+  EXPECT_CALL(*mock_change3, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change3, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change3, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change3);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // The third change should not be composed with the previous.
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change3));
+  EXPECT_EQ(mock_change3, protector_service_->GetLastChange());
+
+  protector_service_->DismissChange(mock_change3);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change3));
+  EXPECT_FALSE(protector_service_->GetLastChange());
+}
+
+IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowCompositeAndOther) {
+  GURL url1("http://example.com/");
+  GURL url2("http://example.net/");
+
+  // Show the first change.
+  EXPECT_CALL(*mock_change_, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change_, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change_, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change_);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
+  EXPECT_EQ(mock_change_, protector_service_->GetLastChange());
+
+  // ProtectService will own this change instance as well.
+  MockSettingChange* mock_change2 = new NiceMock<MockSettingChange>();
+  // Show the second change.
+  EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change2);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // Now ProtectorService should be showing a single composite change.
+  BaseSettingChange* composite_change = protector_service_->GetLastChange();
+  ASSERT_TRUE(composite_change);
+  EXPECT_TRUE(IsGlobalErrorActive(composite_change));
+
+  // Show the third change, with the same URL as 1st and 2nd.
+  MockSettingChange* mock_change3 = new NiceMock<MockSettingChange>();
+  EXPECT_CALL(*mock_change3, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change3, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change3, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change3);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // The third change should be composed with the previous.
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change3));
+  EXPECT_EQ(composite_change, protector_service_->GetLastChange());
+  EXPECT_TRUE(IsGlobalErrorActive(composite_change));
+
+  // Show the 4th change, now with a different URL.
+  MockSettingChange* mock_change4 = new NiceMock<MockSettingChange>();
+  EXPECT_CALL(*mock_change4, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change4, GetNewSettingURL()).WillRepeatedly(Return(url2));
+  EXPECT_CALL(*mock_change4, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change4);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // The 4th change is shown independently.
+  EXPECT_TRUE(IsGlobalErrorActive(composite_change));
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change4));
+  EXPECT_EQ(mock_change4, protector_service_->GetLastChange());
+
+  protector_service_->DismissChange(composite_change);
+  protector_service_->DismissChange(mock_change4);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_FALSE(IsGlobalErrorActive(composite_change));
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change4));
+  EXPECT_FALSE(protector_service_->GetLastChange());
+}
+
+IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, ShowCompositeAndDismissSingle) {
+  GURL url1("http://example.com/");
+  GURL url2("http://example.net/");
+
+  // Show the first change.
+  EXPECT_CALL(*mock_change_, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change_, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change_, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change_);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
+  EXPECT_EQ(mock_change_, protector_service_->GetLastChange());
+
+  // ProtectService will own this change instance as well.
+  MockSettingChange* mock_change2 = new NiceMock<MockSettingChange>();
+  // Show the second change.
+  EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change2);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // Now ProtectorService should be showing a single composite change.
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change_));
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change2));
+
+  BaseSettingChange* composite_change = protector_service_->GetLastChange();
+  ASSERT_TRUE(composite_change);
+  EXPECT_TRUE(IsGlobalErrorActive(composite_change));
+
+  // Show the third change with a different URL.
+  MockSettingChange* mock_change3 = new NiceMock<MockSettingChange>();
+  EXPECT_CALL(*mock_change3, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change3, GetNewSettingURL()).WillRepeatedly(Return(url2));
+  EXPECT_CALL(*mock_change3, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change3);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // The third change should not be composed with the previous.
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change3));
+  EXPECT_TRUE(IsGlobalErrorActive(composite_change));
+  EXPECT_EQ(mock_change3, protector_service_->GetLastChange());
+
+  // Now dismiss the first change.
+  protector_service_->DismissChange(mock_change_);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // This should effectively dismiss the whole composite change.
+  EXPECT_FALSE(IsGlobalErrorActive(composite_change));
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change3));
+  EXPECT_EQ(mock_change3, protector_service_->GetLastChange());
+
+  protector_service_->DismissChange(mock_change3);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change3));
+  EXPECT_FALSE(protector_service_->GetLastChange());
+}
+
+// Verifies that changes with different URLs but same domain are merged.
+IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, SameDomainDifferentURLs) {
+  GURL url1("http://www.example.com/abc");
+  GURL url2("http://example.com/def");
+
+  // Show the first change with some non-empty URL.
+  EXPECT_CALL(*mock_change_, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change_, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change_, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change_);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
+  EXPECT_EQ(mock_change_, protector_service_->GetLastChange());
+
+  // ProtectService will own this change instance as well.
+  MockSettingChange* mock_change2 = new NiceMock<MockSettingChange>();
+  // Show the second change with another non-empty URL having same domain.
+  EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, GetNewSettingURL()).WillRepeatedly(Return(url2));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change2);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // Changes should be merged.
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change_));
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change2));
+
+  BaseSettingChange* composite_change = protector_service_->GetLastChange();
+  ASSERT_TRUE(composite_change);
+  EXPECT_TRUE(IsGlobalErrorActive(composite_change));
+
+  protector_service_->DismissChange(composite_change);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_FALSE(IsGlobalErrorActive(composite_change));
+  EXPECT_FALSE(protector_service_->GetLastChange());
+}
+
+// Verifies that changes with different Google URLs are merged.
+IN_PROC_BROWSER_TEST_F(ProtectorServiceTest, DifferentGoogleDomains) {
+  GURL url1("http://www.google.com/search?q=");
+  GURL url2("http://google.ru/search?q=");
+
+  // Show the first change with some non-empty URL.
+  EXPECT_CALL(*mock_change_, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change_, GetNewSettingURL()).WillRepeatedly(Return(url1));
+  EXPECT_CALL(*mock_change_, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change_);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_TRUE(IsGlobalErrorActive(mock_change_));
+  EXPECT_EQ(mock_change_, protector_service_->GetLastChange());
+
+  // ProtectService will own this change instance as well.
+  MockSettingChange* mock_change2 = new NiceMock<MockSettingChange>();
+  // Show the second change with another non-empty URL having same domain.
+  EXPECT_CALL(*mock_change2, MockInit(browser()->profile())).
+      WillOnce(Return(true));
+  EXPECT_CALL(*mock_change2, GetNewSettingURL()).WillRepeatedly(Return(url2));
+  EXPECT_CALL(*mock_change2, CanBeMerged()).WillRepeatedly(Return(true));
+  protector_service_->ShowChange(mock_change2);
+  ui_test_utils::RunAllPendingInMessageLoop();
+
+  // Changes should be merged.
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change_));
+  EXPECT_FALSE(IsGlobalErrorActive(mock_change2));
+
+  BaseSettingChange* composite_change = protector_service_->GetLastChange();
+  ASSERT_TRUE(composite_change);
+  EXPECT_TRUE(IsGlobalErrorActive(composite_change));
+
+  protector_service_->DismissChange(composite_change);
+  ui_test_utils::RunAllPendingInMessageLoop();
+  EXPECT_FALSE(IsGlobalErrorActive(composite_change));
+  EXPECT_FALSE(protector_service_->GetLastChange());
+}
+
 // TODO(ivankr): Timeout test.
 
 }  // namespace protector
diff --git a/chrome/browser/protector/session_startup_change.cc b/chrome/browser/protector/session_startup_change.cc
index c1d6b19..2c76770 100644
--- a/chrome/browser/protector/session_startup_change.cc
+++ b/chrome/browser/protector/session_startup_change.cc
@@ -43,10 +43,16 @@ class SessionStartupChange : public BasePrefsChange {
   virtual string16 GetBubbleMessage() const OVERRIDE;
   virtual string16 GetApplyButtonText() const OVERRIDE;
   virtual string16 GetDiscardButtonText() const OVERRIDE;
+  virtual DisplayName GetApplyDisplayName() const OVERRIDE;
+  virtual GURL GetNewSettingURL() const OVERRIDE;
 
  private:
   virtual ~SessionStartupChange();
 
+  // Returns the first URL among new startup pages. Returns an empty URL if
+  // there are no new startup pages.
+  GURL GetFirstNewURL() const;
+
   // Opens all tabs in |tabs| and makes them pinned.
   void OpenPinnedTabs(Browser* browser, const PinnedTabCodec::Tabs& tabs);
 
@@ -139,26 +145,43 @@ string16 SessionStartupChange::GetApplyButtonText() const {
   if (new_startup_pref_.type == SessionStartupPref::LAST)
       return l10n_util::GetStringUTF16(IDS_CHANGE_STARTUP_SETTINGS_RESTORE);
 
-  string16 first_url;
-  if (new_startup_pref_.type == SessionStartupPref::URLS &&
-      !new_startup_pref_.urls.empty()) {
-    // Display the domain name of the first statrup URL.
-    first_url = UTF8ToUTF16(new_startup_pref_.urls[0].host());
-  } else if (!new_pinned_tabs_.empty()) {
-    // Start with NTP or no URLs (basically the same): display the domain name
-    // of the first pinned tab, if any.
-    first_url = UTF8ToUTF16(new_pinned_tabs_[0].url.host());
-  }
-  return first_url.empty() ?
+  // Display the domain name of the first startup/pinned URL.
+  string16 first_domain = UTF8ToUTF16(GetFirstNewURL().host());
+  return first_domain.empty() ?
       l10n_util::GetStringUTF16(IDS_CHANGE_STARTUP_SETTINGS_NTP) :
       l10n_util::GetStringFUTF16(IDS_CHANGE_STARTUP_SETTINGS_URLS,
-                                 first_url);
+                                 first_domain);
 }
 
 string16 SessionStartupChange::GetDiscardButtonText() const {
   return l10n_util::GetStringUTF16(IDS_KEEP_SETTING);
 }
 
+BaseSettingChange::DisplayName
+SessionStartupChange::GetApplyDisplayName() const {
+  string16 first_domain = UTF8ToUTF16(GetFirstNewURL().host());
+  return first_domain.empty() ?
+      BaseSettingChange::GetApplyDisplayName() :
+      DisplayName(kSessionStartupChangeNamePriority, first_domain);
+}
+
+GURL SessionStartupChange::GetNewSettingURL() const {
+  VLOG(1) << "HP URL: " << GetFirstNewURL().spec();
+  return GetFirstNewURL();
+}
+
+GURL SessionStartupChange::GetFirstNewURL() const {
+  // TODO(ivankr): this actually should return the first URL present in new
+  // startup prefs AND not in old.
+  if (new_startup_pref_.type == SessionStartupPref::URLS &&
+      !new_startup_pref_.urls.empty()) {
+    return new_startup_pref_.urls[0];
+  }
+  if (!new_pinned_tabs_.empty())
+    return new_pinned_tabs_[0].url;
+  return GURL();
+}
+
 void SessionStartupChange::OpenPinnedTabs(
     Browser* browser,
     const PinnedTabCodec::Tabs& tabs) {
diff --git a/chrome/browser/protector/session_startup_change_unittest.cc b/chrome/browser/protector/session_startup_change_unittest.cc
index 8809853..daac359 100644
--- a/chrome/browser/protector/session_startup_change_unittest.cc
+++ b/chrome/browser/protector/session_startup_change_unittest.cc
@@ -18,6 +18,11 @@ namespace {
 
 const char kStartupUrl1[] = "http://google.com";
 const char kStartupUrl2[] = "http://example.com";
+const char kStartupHost1[] = "google.com";
+const char kStartupHost2[] = "example.com";
+
+const BaseSettingChange::DisplayName kNoDisplayName(
+    BaseSettingChange::kDefaultNamePriority, string16());
 
 }  // namespace
 
@@ -89,6 +94,8 @@ TEST_F(SessionStartupChangeTest, ApplyButtonCaptions) {
                                  backup_startup_pref, empty_pinned_tabs_));
   ASSERT_TRUE(change->Init(&profile_));
   EXPECT_EQ(open_ntp_caption, change->GetApplyButtonText());
+  EXPECT_EQ(GURL(), change->GetNewSettingURL());
+  EXPECT_EQ(kNoDisplayName, change->GetApplyDisplayName());
 
   // Pinned tabs count as startup URLs as well.
   PinnedTabCodec::Tabs new_pinned_tabs;
@@ -100,6 +107,8 @@ TEST_F(SessionStartupChangeTest, ApplyButtonCaptions) {
                                  backup_startup_pref, empty_pinned_tabs_));
   ASSERT_TRUE(change->Init(&profile_));
   EXPECT_EQ(open_url2_etc_caption, change->GetApplyButtonText());
+  EXPECT_EQ(GURL(kStartupUrl2), change->GetNewSettingURL());
+  EXPECT_EQ(UTF8ToUTF16(kStartupHost2), change->GetApplyDisplayName().second);
 
   // "Open URLs" with no URLs is the same as "Open NTP".
   initial_startup_pref_.type = SessionStartupPref::URLS;
@@ -108,6 +117,8 @@ TEST_F(SessionStartupChangeTest, ApplyButtonCaptions) {
                                  backup_startup_pref, empty_pinned_tabs_));
   ASSERT_TRUE(change->Init(&profile_));
   EXPECT_EQ(open_ntp_caption, change->GetApplyButtonText());
+  EXPECT_EQ(GURL(), change->GetNewSettingURL());
+  EXPECT_EQ(kNoDisplayName, change->GetApplyDisplayName());
 
   // Single URL.
   initial_startup_pref_.urls.push_back(GURL(kStartupUrl1));
@@ -116,6 +127,8 @@ TEST_F(SessionStartupChangeTest, ApplyButtonCaptions) {
                                  backup_startup_pref, empty_pinned_tabs_));
   ASSERT_TRUE(change->Init(&profile_));
   EXPECT_EQ(open_url1_etc_caption, change->GetApplyButtonText());
+  EXPECT_EQ(GURL(kStartupUrl1), change->GetNewSettingURL());
+  EXPECT_EQ(UTF8ToUTF16(kStartupHost1), change->GetApplyDisplayName().second);
 
   // Multiple URLs: name of the first one used.
   initial_startup_pref_.urls.push_back(GURL(kStartupUrl2));
@@ -124,6 +137,8 @@ TEST_F(SessionStartupChangeTest, ApplyButtonCaptions) {
                                  backup_startup_pref, empty_pinned_tabs_));
   ASSERT_TRUE(change->Init(&profile_));
   EXPECT_EQ(open_url1_etc_caption, change->GetApplyButtonText());
+  EXPECT_EQ(GURL(kStartupUrl1), change->GetNewSettingURL());
+  EXPECT_EQ(UTF8ToUTF16(kStartupHost1), change->GetApplyDisplayName().second);
 
   // Pinned tabs go after the startup URLs.
   change.reset(
@@ -131,6 +146,8 @@ TEST_F(SessionStartupChangeTest, ApplyButtonCaptions) {
                                  backup_startup_pref, empty_pinned_tabs_));
   ASSERT_TRUE(change->Init(&profile_));
   EXPECT_EQ(open_url1_etc_caption, change->GetApplyButtonText());
+  EXPECT_EQ(GURL(kStartupUrl1), change->GetNewSettingURL());
+  EXPECT_EQ(UTF8ToUTF16(kStartupHost1), change->GetApplyDisplayName().second);
 }
 
 }  // namespace protector
diff --git a/chrome/browser/protector/settings_change_global_error.cc b/chrome/browser/protector/settings_change_global_error.cc
index a51103b..9a18a04 100644
--- a/chrome/browser/protector/settings_change_global_error.cc
+++ b/chrome/browser/protector/settings_change_global_error.cc
@@ -165,6 +165,10 @@ string16 SettingsChangeGlobalError::GetBubbleViewCancelButtonLabel() {
 }
 
 void SettingsChangeGlobalError::OnBubbleViewDidClose(Browser* browser) {
+  // The bubble may be closed as the result of RemoveFromProfile call when
+  // merging this error with another one.
+  if (!profile_)
+    return;
   if (!closed_by_button_) {
     BrowserThread::PostDelayedTask(
         BrowserThread::UI, FROM_HERE,
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index be4472b..39761c0 100644
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -1801,6 +1801,8 @@
         'browser/protector/base_prefs_change.h',
         'browser/protector/base_setting_change.cc',
         'browser/protector/base_setting_change.h',
+        'browser/protector/composite_settings_change.cc',
+        'browser/protector/composite_settings_change.h',
         'browser/protector/default_search_provider_change.cc',
         'browser/protector/histograms.cc',
         'browser/protector/histograms.h',
diff --git a/chrome/chrome_tests.gypi b/chrome/chrome_tests.gypi
index 21040cc..789456f 100644
--- a/chrome/chrome_tests.gypi
+++ b/chrome/chrome_tests.gypi
@@ -1616,6 +1616,7 @@
         'browser/profiles/profile_info_cache_unittest.h',
         'browser/profiles/profile_info_util_unittest.cc',
         'browser/profiles/profile_manager_unittest.cc',
+        'browser/protector/composite_settings_change_unittest.cc',
         'browser/protector/prefs_backup_invalid_change_unittest.cc',
         'browser/protector/protected_prefs_watcher_unittest.cc',
         'browser/protector/session_startup_change_unittest.cc',