Add support for response header manipulation in Declarative WebRequest API

BUG=112155
TEST=no


Review URL: https://chromiumcodereview.appspot.com/10451071

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@139509 0039d316-1c4b-4281-b951-d872f2087c98

15 files changed, 561 insertions, 43 deletions

diff --git a/chrome/browser/extensions/api/declarative_webrequest/webrequest_action.cc b/chrome/browser/extensions/api/declarative_webrequest/webrequest_action.cc
index a6b5e0b..271afc1 100644
--- a/chrome/browser/extensions/api/declarative_webrequest/webrequest_action.cc
+++ b/chrome/browser/extensions/api/declarative_webrequest/webrequest_action.cc
@@ -9,6 +9,7 @@
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/stringprintf.h"
+#include "base/string_util.h"
 #include "base/values.h"
 #include "chrome/browser/extensions/api/declarative_webrequest/request_stages.h"
 #include "chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.h"
@@ -79,6 +80,30 @@ scoped_ptr<WebRequestAction> CreateRemoveRequestHeaderAction(
       new WebRequestRemoveRequestHeaderAction(name));
 }
 
+scoped_ptr<WebRequestAction> CreateAddResponseHeaderAction(
+    const base::DictionaryValue* dict,
+    std::string* error,
+    bool* bad_message) {
+  std::string name;
+  std::string value;
+  INPUT_FORMAT_VALIDATE(dict->GetString(keys::kNameKey, &name));
+  INPUT_FORMAT_VALIDATE(dict->GetString(keys::kValueKey, &value));
+  return scoped_ptr<WebRequestAction>(
+      new WebRequestAddResponseHeaderAction(name, value));
+}
+
+scoped_ptr<WebRequestAction> CreateRemoveResponseHeaderAction(
+    const base::DictionaryValue* dict,
+    std::string* error,
+    bool* bad_message) {
+  std::string name;
+  std::string value;
+  INPUT_FORMAT_VALIDATE(dict->GetString(keys::kNameKey, &name));
+  bool has_value = dict->GetString(keys::kValueKey, &value);
+  return scoped_ptr<WebRequestAction>(
+      new WebRequestRemoveResponseHeaderAction(name, value, has_value));
+}
+
 scoped_ptr<WebRequestAction> CreateIgnoreRulesAction(
     const base::DictionaryValue* dict,
     std::string* error,
@@ -103,6 +128,8 @@ struct WebRequestActionFactory {
   std::map<std::string, FactoryMethod> factory_methods;
 
   WebRequestActionFactory() {
+    factory_methods[keys::kAddResponseHeaderType] =
+        &CreateAddResponseHeaderAction;
     factory_methods[keys::kCancelRequestType] =
         &CallConstructorFactoryMethod<WebRequestCancelAction>;
     factory_methods[keys::kRedirectRequestType] =
@@ -116,6 +143,8 @@ struct WebRequestActionFactory {
         &CreateSetRequestHeaderAction;
     factory_methods[keys::kRemoveRequestHeaderType] =
         &CreateRemoveRequestHeaderAction;
+    factory_methods[keys::kRemoveResponseHeaderType] =
+        &CreateRemoveResponseHeaderAction;
     factory_methods[keys::kIgnoreRulesType] =
         &CreateIgnoreRulesAction;
   }
@@ -198,13 +227,15 @@ scoped_ptr<WebRequestActionSet> WebRequestActionSet::Create(
 std::list<LinkedPtrEventResponseDelta> WebRequestActionSet::CreateDeltas(
     net::URLRequest* request,
     RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
     const std::string& extension_id,
     const base::Time& extension_install_time) const {
   std::list<LinkedPtrEventResponseDelta> result;
   for (Actions::const_iterator i = actions_.begin(); i != actions_.end(); ++i) {
     if ((*i)->GetStages() & request_stage) {
       LinkedPtrEventResponseDelta delta = (*i)->CreateDelta(request,
-          request_stage, extension_id, extension_install_time);
+          request_stage, optional_request_data, extension_id,
+          extension_install_time);
       if (delta.get())
         result.push_back(delta);
     }
@@ -240,6 +271,7 @@ WebRequestAction::Type WebRequestCancelAction::GetType() const {
 LinkedPtrEventResponseDelta WebRequestCancelAction::CreateDelta(
     net::URLRequest* request,
     RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
     const std::string& extension_id,
     const base::Time& extension_install_time) const {
   CHECK(request_stage & GetStages());
@@ -270,6 +302,7 @@ WebRequestAction::Type WebRequestRedirectAction::GetType() const {
 LinkedPtrEventResponseDelta WebRequestRedirectAction::CreateDelta(
     net::URLRequest* request,
     RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
     const std::string& extension_id,
     const base::Time& extension_install_time) const {
   CHECK(request_stage & GetStages());
@@ -305,6 +338,7 @@ LinkedPtrEventResponseDelta
 WebRequestRedirectToTransparentImageAction::CreateDelta(
     net::URLRequest* request,
     RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
     const std::string& extension_id,
     const base::Time& extension_install_time) const {
   CHECK(request_stage & GetStages());
@@ -338,6 +372,7 @@ LinkedPtrEventResponseDelta
 WebRequestRedirectToEmptyDocumentAction::CreateDelta(
     net::URLRequest* request,
     RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
     const std::string& extension_id,
     const base::Time& extension_install_time) const {
   CHECK(request_stage & GetStages());
@@ -374,6 +409,7 @@ LinkedPtrEventResponseDelta
 WebRequestSetRequestHeaderAction::CreateDelta(
     net::URLRequest* request,
     RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
     const std::string& extension_id,
     const base::Time& extension_install_time) const {
   CHECK(request_stage & GetStages());
@@ -408,6 +444,7 @@ LinkedPtrEventResponseDelta
 WebRequestRemoveRequestHeaderAction::CreateDelta(
     net::URLRequest* request,
     RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
     const std::string& extension_id,
     const base::Time& extension_install_time) const {
   CHECK(request_stage & GetStages());
@@ -419,6 +456,107 @@ WebRequestRemoveRequestHeaderAction::CreateDelta(
 }
 
 //
+// WebRequestAddResponseHeaderAction
+//
+
+WebRequestAddResponseHeaderAction::WebRequestAddResponseHeaderAction(
+    const std::string& name,
+    const std::string& value)
+    : name_(name),
+      value_(value) {
+}
+
+WebRequestAddResponseHeaderAction::~WebRequestAddResponseHeaderAction() {}
+
+int WebRequestAddResponseHeaderAction::GetStages() const {
+  return ON_HEADERS_RECEIVED;
+}
+
+WebRequestAction::Type
+WebRequestAddResponseHeaderAction::GetType() const {
+  return WebRequestAction::ACTION_ADD_RESPONSE_HEADER;
+}
+
+LinkedPtrEventResponseDelta
+WebRequestAddResponseHeaderAction::CreateDelta(
+    net::URLRequest* request,
+    RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
+    const std::string& extension_id,
+    const base::Time& extension_install_time) const {
+  CHECK(request_stage & GetStages());
+  LinkedPtrEventResponseDelta result(
+      new extension_web_request_api_helpers::EventResponseDelta(
+          extension_id, extension_install_time));
+
+  net::HttpResponseHeaders* headers =
+      optional_request_data.original_response_headers;
+  if (!headers)
+    return result;
+
+  // Don't generate the header if it exists already.
+  if (headers->HasHeaderValue(name_, value_))
+    return result;
+
+  result->added_response_headers.push_back(make_pair(name_, value_));
+  return result;
+}
+
+//
+// WebRequestRemoveResponseHeaderAction
+//
+
+WebRequestRemoveResponseHeaderAction::WebRequestRemoveResponseHeaderAction(
+    const std::string& name,
+    const std::string& value,
+    bool has_value)
+    : name_(name),
+      value_(value),
+      has_value_(has_value) {
+}
+
+WebRequestRemoveResponseHeaderAction::~WebRequestRemoveResponseHeaderAction() {}
+
+int WebRequestRemoveResponseHeaderAction::GetStages() const {
+  return ON_HEADERS_RECEIVED;
+}
+
+WebRequestAction::Type
+WebRequestRemoveResponseHeaderAction::GetType() const {
+  return WebRequestAction::ACTION_REMOVE_RESPONSE_HEADER;
+}
+
+LinkedPtrEventResponseDelta
+WebRequestRemoveResponseHeaderAction::CreateDelta(
+    net::URLRequest* request,
+    RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
+    const std::string& extension_id,
+    const base::Time& extension_install_time) const {
+  CHECK(request_stage & GetStages());
+  LinkedPtrEventResponseDelta result(
+      new extension_web_request_api_helpers::EventResponseDelta(
+          extension_id, extension_install_time));
+  net::HttpResponseHeaders* headers =
+      optional_request_data.original_response_headers;
+  if (!headers)
+    return result;
+  void* iter = NULL;
+  std::string current_value;
+  while (headers->EnumerateHeader(&iter, name_, &current_value)) {
+    if (has_value_ &&
+           (current_value.size() != value_.size() ||
+            !std::equal(current_value.begin(), current_value.end(),
+                        value_.begin(),
+                        base::CaseInsensitiveCompare<char>()))) {
+      continue;
+    }
+    result->deleted_response_headers.push_back(make_pair(name_, current_value));
+  }
+  return result;
+}
+
+//
 // WebRequestIgnoreRulesAction
 //
 
@@ -445,6 +583,7 @@ int WebRequestIgnoreRulesAction::GetMinimumPriority() const {
 LinkedPtrEventResponseDelta WebRequestIgnoreRulesAction::CreateDelta(
     net::URLRequest* request,
     RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data,
     const std::string& extension_id,
     const base::Time& extension_install_time) const {
   CHECK(request_stage & GetStages());
diff --git a/chrome/browser/extensions/api/declarative_webrequest/webrequest_action.h b/chrome/browser/extensions/api/declarative_webrequest/webrequest_action.h
index 73f37f5..5c8a6cb 100644
--- a/chrome/browser/extensions/api/declarative_webrequest/webrequest_action.h
+++ b/chrome/browser/extensions/api/declarative_webrequest/webrequest_action.h
@@ -13,6 +13,7 @@
 #include "base/compiler_specific.h"
 #include "base/memory/linked_ptr.h"
 #include "chrome/browser/extensions/api/declarative_webrequest/request_stages.h"
+#include "chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.h"
 #include "chrome/common/extensions/api/events.h"
 #include "googleurl/src/gurl.h"
 
@@ -48,6 +49,8 @@ class WebRequestAction {
     ACTION_REDIRECT_TO_EMPTY_DOCUMENT,
     ACTION_SET_REQUEST_HEADER,
     ACTION_REMOVE_REQUEST_HEADER,
+    ACTION_ADD_RESPONSE_HEADER,
+    ACTION_REMOVE_RESPONSE_HEADER,
     ACTION_IGNORE_RULES,
   };
 
@@ -80,6 +83,7 @@ class WebRequestAction {
   virtual LinkedPtrEventResponseDelta CreateDelta(
       net::URLRequest* request,
       RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
       const std::string& extension_id,
       const base::Time& extension_install_time) const = 0;
 };
@@ -109,6 +113,7 @@ class WebRequestActionSet {
   std::list<LinkedPtrEventResponseDelta> CreateDeltas(
       net::URLRequest* request,
       RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
       const std::string& extension_id,
       const base::Time& extension_install_time) const;
 
@@ -140,6 +145,7 @@ class WebRequestCancelAction : public WebRequestAction {
   virtual LinkedPtrEventResponseDelta CreateDelta(
       net::URLRequest* request,
       RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
       const std::string& extension_id,
       const base::Time& extension_install_time) const OVERRIDE;
 
@@ -159,6 +165,7 @@ class WebRequestRedirectAction : public WebRequestAction {
   virtual LinkedPtrEventResponseDelta CreateDelta(
       net::URLRequest* request,
       RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
       const std::string& extension_id,
       const base::Time& extension_install_time) const OVERRIDE;
 
@@ -180,6 +187,7 @@ class WebRequestRedirectToTransparentImageAction : public WebRequestAction {
   virtual LinkedPtrEventResponseDelta CreateDelta(
       net::URLRequest* request,
       RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
       const std::string& extension_id,
       const base::Time& extension_install_time) const OVERRIDE;
 
@@ -200,6 +208,7 @@ class WebRequestRedirectToEmptyDocumentAction : public WebRequestAction {
   virtual LinkedPtrEventResponseDelta CreateDelta(
       net::URLRequest* request,
       RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
       const std::string& extension_id,
       const base::Time& extension_install_time) const OVERRIDE;
 
@@ -220,6 +229,7 @@ class WebRequestSetRequestHeaderAction : public WebRequestAction {
   virtual LinkedPtrEventResponseDelta CreateDelta(
       net::URLRequest* request,
       RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
       const std::string& extension_id,
       const base::Time& extension_install_time) const OVERRIDE;
 
@@ -241,6 +251,7 @@ class WebRequestRemoveRequestHeaderAction : public WebRequestAction {
   virtual LinkedPtrEventResponseDelta CreateDelta(
       net::URLRequest* request,
       RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
       const std::string& extension_id,
       const base::Time& extension_install_time) const OVERRIDE;
 
@@ -249,6 +260,54 @@ class WebRequestRemoveRequestHeaderAction : public WebRequestAction {
   DISALLOW_COPY_AND_ASSIGN(WebRequestRemoveRequestHeaderAction);
 };
 
+// Action that instructs to add a response header.
+class WebRequestAddResponseHeaderAction : public WebRequestAction {
+ public:
+  WebRequestAddResponseHeaderAction(const std::string& name,
+                                    const std::string& value);
+  virtual ~WebRequestAddResponseHeaderAction();
+
+  // Implementation of WebRequestAction:
+  virtual int GetStages() const OVERRIDE;
+  virtual Type GetType() const OVERRIDE;
+  virtual LinkedPtrEventResponseDelta CreateDelta(
+      net::URLRequest* request,
+      RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
+      const std::string& extension_id,
+      const base::Time& extension_install_time) const OVERRIDE;
+
+ private:
+  std::string name_;
+  std::string value_;
+  DISALLOW_COPY_AND_ASSIGN(WebRequestAddResponseHeaderAction);
+};
+
+// Action that instructs to remove a response header.
+class WebRequestRemoveResponseHeaderAction : public WebRequestAction {
+ public:
+  explicit WebRequestRemoveResponseHeaderAction(const std::string& name,
+                                                const std::string& value,
+                                                bool has_value);
+  virtual ~WebRequestRemoveResponseHeaderAction();
+
+  // Implementation of WebRequestAction:
+  virtual int GetStages() const OVERRIDE;
+  virtual Type GetType() const OVERRIDE;
+  virtual LinkedPtrEventResponseDelta CreateDelta(
+      net::URLRequest* request,
+      RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
+      const std::string& extension_id,
+      const base::Time& extension_install_time) const OVERRIDE;
+
+ private:
+  std::string name_;
+  std::string value_;
+  bool has_value_;
+  DISALLOW_COPY_AND_ASSIGN(WebRequestRemoveResponseHeaderAction);
+};
+
 // Action that instructs to ignore rules below a certain priority.
 class WebRequestIgnoreRulesAction : public WebRequestAction {
  public:
@@ -262,6 +321,7 @@ class WebRequestIgnoreRulesAction : public WebRequestAction {
   virtual LinkedPtrEventResponseDelta CreateDelta(
       net::URLRequest* request,
       RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data,
       const std::string& extension_id,
       const base::Time& extension_install_time) const OVERRIDE;
 
@@ -271,7 +331,7 @@ class WebRequestIgnoreRulesAction : public WebRequestAction {
 };
 
 // TODO(battre) Implement further actions:
-// Redirect to constant url, Redirect by RegEx, Set header, Remove header, ...
+// Redirect by RegEx, Cookie manipulations, ...
 
 }  // namespace extensions
 
diff --git a/chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.cc b/chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.cc
index ea51728..a6d2a6c 100644
--- a/chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.cc
+++ b/chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.cc
@@ -20,6 +20,8 @@ const char kUrlKey[] = "url";
 const char kValueKey[] = "value";
 
 // Values of dictionaries, in particular instance types
+const char kAddResponseHeaderType[] =
+    "declarativeWebRequest.AddResponseHeader";
 const char kCancelRequestType[] = "declarativeWebRequest.CancelRequest";
 const char kIgnoreRulesType[] = "declarativeWebRequest.IgnoreRules";
 const char kRedirectRequestType[] = "declarativeWebRequest.RedirectRequest";
@@ -29,6 +31,8 @@ const char kRedirectToTransparentImageType[] =
     "declarativeWebRequest.RedirectToTransparentImage";
 const char kRemoveRequestHeaderType[] =
     "declarativeWebRequest.RemoveRequestHeader";
+const char kRemoveResponseHeaderType[] =
+    "declarativeWebRequest.RemoveResponseHeader";
 const char kRequestMatcherType[] = "declarativeWebRequest.RequestMatcher";
 const char kSetRequestHeaderType[] = "declarativeWebRequest.SetRequestHeader";
 
diff --git a/chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.h b/chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.h
index 14fb873..86984d0 100644
--- a/chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.h
+++ b/chrome/browser/extensions/api/declarative_webrequest/webrequest_constants.h
@@ -24,12 +24,14 @@ extern const char kUrlKey[];
 extern const char kValueKey[];
 
 // Values of dictionaries, in particular instance types
+extern const char kAddResponseHeaderType[];
 extern const char kCancelRequestType[];
 extern const char kIgnoreRulesType[];
 extern const char kRedirectRequestType[];
 extern const char kRedirectToEmptyDocumentType[];
 extern const char kRedirectToTransparentImageType[];
 extern const char kRemoveRequestHeaderType[];
+extern const char kRemoveResponseHeaderType[];
 extern const char kRequestMatcherType[];
 extern const char kSetRequestHeaderType[];
 
diff --git a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.cc b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.cc
index cac8386..1fc8e40 100644
--- a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.cc
+++ b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.cc
@@ -87,9 +87,10 @@ scoped_ptr<WebRequestRule> WebRequestRule::Create(
 
 std::list<LinkedPtrEventResponseDelta> WebRequestRule::CreateDeltas(
     net::URLRequest* request,
-    RequestStages request_stage) const {
-  return actions_->CreateDeltas(request, request_stage, id_.first,
-      extension_installation_time_);
+    RequestStages request_stage,
+    const OptionalRequestData& optional_request_data) const {
+  return actions_->CreateDeltas(request, request_stage, optional_request_data,
+      id_.first, extension_installation_time_);
 }
 
 int WebRequestRule::GetMinimumPriority() const {
diff --git a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.h b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.h
index 5187688..d12e2fc 100644
--- a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.h
+++ b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.h
@@ -25,6 +25,7 @@ struct EventResponseDelta;
 }
 
 namespace net {
+class HttpResponseHeaders;
 class URLRequest;
 }
 
@@ -41,6 +42,13 @@ class WebRequestRule {
   typedef std::pair<ExtensionId, RuleId> GlobalRuleId;
   typedef int Priority;
 
+  // Container to pass additional information about requests that are not
+  // available in all request stages.
+  struct OptionalRequestData {
+    OptionalRequestData() : original_response_headers(NULL) {}
+    net::HttpResponseHeaders* original_response_headers;
+  };
+
   WebRequestRule(const GlobalRuleId& id,
                  base::Time extension_installation_time,
                  scoped_ptr<WebRequestConditionSet> conditions,
@@ -64,7 +72,8 @@ class WebRequestRule {
 
   std::list<LinkedPtrEventResponseDelta> CreateDeltas(
       net::URLRequest* request,
-      RequestStages request_stage) const;
+      RequestStages request_stage,
+      const OptionalRequestData& optional_request_data) const;
 
   // Returns the minimum priority of rules that may be evaluated after
   // this rule. Defaults to MAX_INT. Only valid if the conditions of this rule
diff --git a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.cc b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.cc
index 2da96a7..ea2869a 100644
--- a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.cc
+++ b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.cc
@@ -43,7 +43,8 @@ WebRequestRulesRegistry::GetMatches(net::URLRequest* request,
 
 std::list<LinkedPtrEventResponseDelta> WebRequestRulesRegistry::CreateDeltas(
     net::URLRequest* request,
-    RequestStages request_stage) {
+    RequestStages request_stage,
+    const WebRequestRule::OptionalRequestData& optional_request_data) {
   std::set<WebRequestRule::GlobalRuleId> matches =
       GetMatches(request, request_stage);
 
@@ -93,7 +94,7 @@ std::list<LinkedPtrEventResponseDelta> WebRequestRulesRegistry::CreateDeltas(
       continue;
 
     std::list<LinkedPtrEventResponseDelta> rule_result =
-        rule->CreateDeltas(request, request_stage);
+        rule->CreateDeltas(request, request_stage, optional_request_data);
     result.splice(result.begin(), rule_result);
 
     min_priorities[extension_id] = std::max(current_min_priority,
diff --git a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.h b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.h
index 3beff8f..b71406f 100644
--- a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.h
+++ b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.h
@@ -33,7 +33,6 @@ class URLRequest;
 namespace extensions {
 
 class RulesRegistryService;
-class WebRequestRule;
 
 // The WebRequestRulesRegistry is responsible for managing
 // the internal representation of rules for the Declarative Web Request API.
@@ -76,7 +75,9 @@ class WebRequestRulesRegistry : public RulesRegistryWithCache {
   // Returns which modifications should be executed on the network request
   // according to the rules registered in this registry.
   std::list<LinkedPtrEventResponseDelta> CreateDeltas(
-      net::URLRequest* request, RequestStages request_stage);
+      net::URLRequest* request,
+      RequestStages request_stage,
+      const WebRequestRule::OptionalRequestData& optional_request_data);
 
   // Implementation of RulesRegistryWithCache:
   virtual std::string AddRulesImpl(
diff --git a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry_unittest.cc b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry_unittest.cc
index 9020ed5..7d322b4 100644
--- a/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry_unittest.cc
+++ b/chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry_unittest.cc
@@ -336,7 +336,8 @@ TEST_F(WebRequestRulesRegistryTest, Precedences) {
   GURL url("http://www.google.com");
   TestURLRequest request(url, NULL);
   std::list<LinkedPtrEventResponseDelta> deltas =
-      registry->CreateDeltas(&request, ON_BEFORE_REQUEST);
+      registry->CreateDeltas(&request, ON_BEFORE_REQUEST,
+          WebRequestRule::OptionalRequestData());
 
   // The second extension is installed later and will win for this reason
   // in conflict resolution.
@@ -382,7 +383,8 @@ TEST_F(WebRequestRulesRegistryTest, Priorities) {
   GURL url("http://www.google.com/index.html");
   TestURLRequest request(url, NULL);
   std::list<LinkedPtrEventResponseDelta> deltas =
-      registry->CreateDeltas(&request, ON_BEFORE_REQUEST);
+      registry->CreateDeltas(&request, ON_BEFORE_REQUEST,
+          WebRequestRule::OptionalRequestData());
 
   // The redirect by the first extension is ignored due to the ignore rule.
   ASSERT_EQ(1u, deltas.size());
diff --git a/chrome/browser/extensions/api/web_request/web_request_api.cc b/chrome/browser/extensions/api/web_request/web_request_api.cc
index e91e8e9..5a73e14 100644
--- a/chrome/browser/extensions/api/web_request/web_request_api.cc
+++ b/chrome/browser/extensions/api/web_request/web_request_api.cc
@@ -16,6 +16,7 @@
 #include "base/values.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_content_browser_client.h"
+#include "chrome/browser/extensions/api/declarative_webrequest/webrequest_rule.h"
 #include "chrome/browser/extensions/api/declarative_webrequest/webrequest_rules_registry.h"
 #include "chrome/browser/extensions/api/web_request/web_request_api_constants.h"
 #include "chrome/browser/extensions/api/web_request/web_request_api_helpers.h"
@@ -488,7 +489,7 @@ int ExtensionWebRequestEventRouter::OnBeforeRequest(
   bool initialize_blocked_requests = false;
 
   initialize_blocked_requests |=
-      ProcessDeclarativeRules(request, extensions::ON_BEFORE_REQUEST);
+      ProcessDeclarativeRules(request, extensions::ON_BEFORE_REQUEST, NULL);
 
   int extra_info_spec = 0;
   std::vector<const EventListener*> listeners =
@@ -536,7 +537,8 @@ int ExtensionWebRequestEventRouter::OnBeforeSendHeaders(
   bool initialize_blocked_requests = false;
 
   initialize_blocked_requests |=
-      ProcessDeclarativeRules(request, extensions::ON_BEFORE_SEND_HEADERS);
+      ProcessDeclarativeRules(request, extensions::ON_BEFORE_SEND_HEADERS,
+                              NULL);
 
   int extra_info_spec = 0;
   std::vector<const EventListener*> listeners =
@@ -616,40 +618,54 @@ int ExtensionWebRequestEventRouter::OnHeadersReceived(
   if (!profile || helpers::HideRequestForURL(request->url()))
     return net::OK;
 
+  bool initialize_blocked_requests = false;
+
+  initialize_blocked_requests |=
+      ProcessDeclarativeRules(request, extensions::ON_HEADERS_RECEIVED,
+                              original_response_headers);
+
   int extra_info_spec = 0;
   std::vector<const EventListener*> listeners =
       GetMatchingListeners(profile, extension_info_map,
                            keys::kOnHeadersReceived, request,
                            &extra_info_spec);
 
-  if (listeners.empty())
-    return net::OK;
-
-  if (GetAndSetSignaled(request->identifier(), kOnHeadersReceived))
-    return net::OK;
+  if (!listeners.empty() &&
+      !GetAndSetSignaled(request->identifier(), kOnHeadersReceived)) {
+    ListValue args;
+    DictionaryValue* dict = new DictionaryValue();
+    ExtractRequestInfo(request, dict);
+    dict->SetString(keys::kStatusLineKey,
+        original_response_headers->GetStatusLine());
+    if (extra_info_spec & ExtraInfoSpec::RESPONSE_HEADERS) {
+      dict->Set(keys::kResponseHeadersKey,
+          GetResponseHeadersList(original_response_headers));
+    }
+    args.Append(dict);
 
-  ListValue args;
-  DictionaryValue* dict = new DictionaryValue();
-  ExtractRequestInfo(request, dict);
-  dict->SetString(keys::kStatusLineKey,
-      original_response_headers->GetStatusLine());
-  if (extra_info_spec & ExtraInfoSpec::RESPONSE_HEADERS) {
-    dict->Set(keys::kResponseHeadersKey,
-        GetResponseHeadersList(original_response_headers));
+    initialize_blocked_requests |=
+        DispatchEvent(profile, request, listeners, args);
   }
-  args.Append(dict);
 
-  if (DispatchEvent(profile, request, listeners, args)) {
-    blocked_requests_[request->identifier()].event = kOnHeadersReceived;
-    blocked_requests_[request->identifier()].callback = callback;
-    blocked_requests_[request->identifier()].net_log = &request->net_log();
-    blocked_requests_[request->identifier()].override_response_headers =
-        override_response_headers;
-    blocked_requests_[request->identifier()].original_response_headers =
-        original_response_headers;
+  if (!initialize_blocked_requests)
+    return net::OK;  // Nobody saw a reason for modifying the request.
+
+  blocked_requests_[request->identifier()].event = kOnHeadersReceived;
+  blocked_requests_[request->identifier()].callback = callback;
+  blocked_requests_[request->identifier()].net_log = &request->net_log();
+  blocked_requests_[request->identifier()].override_response_headers =
+      override_response_headers;
+  blocked_requests_[request->identifier()].original_response_headers =
+      original_response_headers;
+
+  if (blocked_requests_[request->identifier()].num_handlers_blocking == 0) {
+    // If there are no blocking handlers, only the declarative rules tried
+    // to modify the request and we can respond synchronously.
+    return ExecuteDeltas(profile, request->identifier(),
+                         false /* call_callback*/);
+  } else {
     return net::ERR_IO_PENDING;
   }
-  return net::OK;
 }
 
 net::NetworkDelegate::AuthRequiredResponse
@@ -1384,7 +1400,8 @@ int ExtensionWebRequestEventRouter::ExecuteDeltas(
 
 bool ExtensionWebRequestEventRouter::ProcessDeclarativeRules(
     net::URLRequest* request,
-    extensions::RequestStages request_stage) {
+    extensions::RequestStages request_stage,
+    net::HttpResponseHeaders* original_response_headers) {
   if (!rules_registry_.get())
     return false;
 
@@ -1393,8 +1410,12 @@ bool ExtensionWebRequestEventRouter::ProcessDeclarativeRules(
   // TODO(battre): Annotate deltas with extension IDs, so that we can
   // - Sort deltas by precedence
   // - Check whether extensions have host permissions.
+  extensions::WebRequestRule::OptionalRequestData optional_request_data;
+  optional_request_data.original_response_headers =
+      original_response_headers;
   std::list<linked_ptr<helpers::EventResponseDelta> > result =
-      rules_registry_->CreateDeltas(request, request_stage);
+      rules_registry_->CreateDeltas(request, request_stage,
+                                    optional_request_data);
 
   base::TimeDelta elapsed_time = start - base::Time::Now();
   UMA_HISTOGRAM_TIMES("Extensions.DeclarativeWebRequestNetworkDelay",
diff --git a/chrome/browser/extensions/api/web_request/web_request_api.h b/chrome/browser/extensions/api/web_request/web_request_api.h
index ee7adf3..846381c 100644
--- a/chrome/browser/extensions/api/web_request/web_request_api.h
+++ b/chrome/browser/extensions/api/web_request/web_request_api.h
@@ -330,10 +330,13 @@ class ExtensionWebRequestEventRouter {
 
   // Evaluates the rules of the declarative webrequest API and stores
   // modifications to the request that result from WebRequestActions as
-  // deltas in |blocked_requests_|. Returns whether any deltas were
-  // generated.
-  bool ProcessDeclarativeRules(net::URLRequest* request,
-                               extensions::RequestStages request_stage);
+  // deltas in |blocked_requests_|. |original_response_headers| should only be
+  // set for the OnHeadersReceived stage and NULL otherwise. Returns whether any
+  // deltas were generated.
+  bool ProcessDeclarativeRules(
+      net::URLRequest* request,
+      extensions::RequestStages request_stage,
+      net::HttpResponseHeaders* original_response_headers);
 
   // Sets the flag that |event_type| has been signaled for |request_id|.
   // Returns the value of the flag before setting it.
diff --git a/chrome/common/extensions/api/declarative_web_request.json b/chrome/common/extensions/api/declarative_web_request.json
index 3e445d2..0ab3222 100644
--- a/chrome/common/extensions/api/declarative_web_request.json
+++ b/chrome/common/extensions/api/declarative_web_request.json
@@ -100,6 +100,45 @@
         }
       },
       {
+        "id": "declarativeWebRequest.AddResponseHeader",
+        "description": "Adds the response header to the response of this web request. As multiple response headers may share the same name, you need to first remove and then add a new response header in order to replace one.",
+        "type": "object",
+        "properties": {
+          "instanceType": {
+            "type": "string", "enum": ["declarativeWebRequest.AddResponseHeader"],
+            "nodoc": true
+          },
+          "name": {
+            "type": "string",
+            "description": "HTTP response header name."
+          },
+          "value": {
+            "type": "string",
+            "description": "HTTP response header value."
+          }
+        }
+      },
+      {
+        "id": "declarativeWebRequest.RemoveResponseHeader",
+        "description": "Removes all response headers of the specified names and values.",
+        "type": "object",
+        "properties": {
+          "instanceType": {
+            "type": "string", "enum": ["declarativeWebRequest.RemoveResponseHeader"],
+            "nodoc": true
+          },
+          "name": {
+            "type": "string",
+            "description": "HTTP request header name (case-insensitive)."
+          },
+          "value": {
+            "type": "string",
+            "description": "HTTP request header value (case-insensitive).",
+            "optional": true
+          }
+        }
+      },
+      {
         "id": "declarativeWebRequest.IgnoreRules",
         "description": "Masks all rules that match the specified criteria.",
         "type": "object",
@@ -125,12 +164,14 @@
           "supportsRules": true,
           "conditions": ["declarativeWebRequest.RequestMatcher"],
           "actions": [
+            "declarativeWebRequest.AddResponseHeader",
             "declarativeWebRequest.CancelRequest",
             "declarativeWebRequest.RedirectRequest",
             "declarativeWebRequest.RedirectToTransparentImage",
             "declarativeWebRequest.RedirectToEmptyDocument",
             "declarativeWebRequest.SetRequestHeader",
             "declarativeWebRequest.RemoveRequestHeader",
+            "declarativeWebRequest.RemoveResponseHeader",
             "declarativeWebRequest.IgnoreRules"
           ]
         }
diff --git a/chrome/common/extensions/docs/declarativeWebRequest.html b/chrome/common/extensions/docs/declarativeWebRequest.html
index 65ee70d..07d2697 100644
--- a/chrome/common/extensions/docs/declarativeWebRequest.html
+++ b/chrome/common/extensions/docs/declarativeWebRequest.html
@@ -251,6 +251,14 @@
                 <ol>
                 </ol>
               </li><li>
+                <a href="#type-declarativeWebRequest.AddResponseHeader">declarativeWebRequest.AddResponseHeader</a>
+                <ol>
+                </ol>
+              </li><li>
+                <a href="#type-declarativeWebRequest.RemoveResponseHeader">declarativeWebRequest.RemoveResponseHeader</a>
+                <ol>
+                </ol>
+              </li><li>
                 <a href="#type-declarativeWebRequest.IgnoreRules">declarativeWebRequest.IgnoreRules</a>
                 <ol>
                 </ol>
@@ -420,6 +428,15 @@ very fast URL matching algorithm for hundreds of thousands of URLs.
                     <div>
                       <div>
           <dt>
+            <a href="declarativeWebRequest.html#type-declarativeWebRequest.AddResponseHeader">declarativeWebRequest.AddResponseHeader</a>
+          </dt>
+          <dd class="todo">
+            Undocumented.
+          </dd>
+        </div>
+                    </div><div>
+                      <div>
+          <dt>
             <a>declarativeWebRequest.CancelRequest</a>
           </dt>
         </div>
@@ -468,6 +485,15 @@ very fast URL matching algorithm for hundreds of thousands of URLs.
                     </div><div>
                       <div>
           <dt>
+            <a href="declarativeWebRequest.html#type-declarativeWebRequest.RemoveResponseHeader">declarativeWebRequest.RemoveResponseHeader</a>
+          </dt>
+          <dd class="todo">
+            Undocumented.
+          </dd>
+        </div>
+                    </div><div>
+                      <div>
+          <dt>
             <a href="declarativeWebRequest.html#type-declarativeWebRequest.IgnoreRules">declarativeWebRequest.IgnoreRules</a>
           </dt>
           <dd class="todo">
@@ -915,6 +941,157 @@ very fast URL matching algorithm for hundreds of thousands of URLs.
           <!-- FUNCTION PARAMETERS -->
         </div>
             </div><div class="apiItem">
+              <a name="type-declarativeWebRequest.AddResponseHeader"></a>
+              <h4>declarativeWebRequest.AddResponseHeader</h4>
+              <div>
+          <dt>
+              <em>
+                <!-- TYPE -->
+                <div style="display:inline">
+                  (
+                    <span id="typeTemplate">
+                      <span>
+                        <span>object</span>
+                      </span>
+                    </span>
+                  )
+                </div>
+              </em>
+          </dt>
+          <dd>Adds the response header to the response of this web request. As multiple response headers may share the same name, you need to first remove and then add a new response header in order to replace one.</dd>
+          <!-- OBJECT PROPERTIES -->
+          <dd>
+            <dl>
+              <div>
+                <div>
+          <dt>
+            <var>name</var>
+              <em>
+                <!-- TYPE -->
+                <div style="display:inline">
+                  (
+                    <span id="typeTemplate">
+                      <span>
+                        <span>string</span>
+                      </span>
+                    </span>
+                  )
+                </div>
+              </em>
+          </dt>
+          <dd>HTTP response header name.</dd>
+          <!-- OBJECT PROPERTIES -->
+          <!-- OBJECT METHODS -->
+          <!-- OBJECT EVENT FIELDS -->
+          <!-- FUNCTION PARAMETERS -->
+        </div>
+              </div><div>
+                <div>
+          <dt>
+            <var>value</var>
+              <em>
+                <!-- TYPE -->
+                <div style="display:inline">
+                  (
+                    <span id="typeTemplate">
+                      <span>
+                        <span>string</span>
+                      </span>
+                    </span>
+                  )
+                </div>
+              </em>
+          </dt>
+          <dd>HTTP response header value.</dd>
+          <!-- OBJECT PROPERTIES -->
+          <!-- OBJECT METHODS -->
+          <!-- OBJECT EVENT FIELDS -->
+          <!-- FUNCTION PARAMETERS -->
+        </div>
+              </div>
+            </dl>
+          </dd>
+          <!-- OBJECT METHODS -->
+          <!-- OBJECT EVENT FIELDS -->
+          <!-- FUNCTION PARAMETERS -->
+        </div>
+            </div><div class="apiItem">
+              <a name="type-declarativeWebRequest.RemoveResponseHeader"></a>
+              <h4>declarativeWebRequest.RemoveResponseHeader</h4>
+              <div>
+          <dt>
+              <em>
+                <!-- TYPE -->
+                <div style="display:inline">
+                  (
+                    <span id="typeTemplate">
+                      <span>
+                        <span>object</span>
+                      </span>
+                    </span>
+                  )
+                </div>
+              </em>
+          </dt>
+          <dd>Removes all response headers of the specified names and values.</dd>
+          <!-- OBJECT PROPERTIES -->
+          <dd>
+            <dl>
+              <div>
+                <div>
+          <dt>
+            <var>name</var>
+              <em>
+                <!-- TYPE -->
+                <div style="display:inline">
+                  (
+                    <span id="typeTemplate">
+                      <span>
+                        <span>string</span>
+                      </span>
+                    </span>
+                  )
+                </div>
+              </em>
+          </dt>
+          <dd>HTTP request header name (case-insensitive).</dd>
+          <!-- OBJECT PROPERTIES -->
+          <!-- OBJECT METHODS -->
+          <!-- OBJECT EVENT FIELDS -->
+          <!-- FUNCTION PARAMETERS -->
+        </div>
+              </div><div>
+                <div>
+          <dt>
+            <var>value</var>
+              <em>
+                <!-- TYPE -->
+                <div style="display:inline">
+                  (
+                    <span class="optional">optional</span>
+                    <span id="typeTemplate">
+                      <span>
+                        <span>string</span>
+                      </span>
+                    </span>
+                  )
+                </div>
+              </em>
+          </dt>
+          <dd>HTTP request header value (case-insensitive).</dd>
+          <!-- OBJECT PROPERTIES -->
+          <!-- OBJECT METHODS -->
+          <!-- OBJECT EVENT FIELDS -->
+          <!-- FUNCTION PARAMETERS -->
+        </div>
+              </div>
+            </dl>
+          </dd>
+          <!-- OBJECT METHODS -->
+          <!-- OBJECT EVENT FIELDS -->
+          <!-- FUNCTION PARAMETERS -->
+        </div>
+            </div><div class="apiItem">
               <a name="type-declarativeWebRequest.IgnoreRules"></a>
               <h4>declarativeWebRequest.IgnoreRules</h4>
               <div>
diff --git a/chrome/renderer/resources/extensions/declarative_webrequest_custom_bindings.js b/chrome/renderer/resources/extensions/declarative_webrequest_custom_bindings.js
index 4d4db1a..5a8d798 100644
--- a/chrome/renderer/resources/extensions/declarative_webrequest_custom_bindings.js
+++ b/chrome/renderer/resources/extensions/declarative_webrequest_custom_bindings.js
@@ -48,6 +48,12 @@ chromeHidden.registerCustomHook('declarativeWebRequest', function(api) {
   chrome.declarativeWebRequest.RemoveRequestHeader = function(parameters) {
     setupInstance(this, parameters, 'RemoveRequestHeader');
   };
+  chrome.declarativeWebRequest.AddResponseHeader = function(parameters) {
+    setupInstance(this, parameters, 'AddResponseHeader');
+  };
+  chrome.declarativeWebRequest.RemoveResponseHeader = function(parameters) {
+    setupInstance(this, parameters, 'RemoveResponseHeader');
+  };
   chrome.declarativeWebRequest.RedirectToTransparentImage =
       function(parameters) {
     setupInstance(this, parameters, 'RedirectToTransparentImage');
diff --git a/chrome/test/data/extensions/api_test/webrequest/test_declarative.js b/chrome/test/data/extensions/api_test/webrequest/test_declarative.js
index be22dd6..e6e621f 100644
--- a/chrome/test/data/extensions/api_test/webrequest/test_declarative.js
+++ b/chrome/test/data/extensions/api_test/webrequest/test_declarative.js
@@ -3,6 +3,8 @@
 // found in the LICENSE file.
 
 var onRequest = chrome.declarativeWebRequest.onRequest;
+var AddResponseHeader =
+    chrome.declarativeWebRequest.AddResponseHeader;
 var RequestMatcher = chrome.declarativeWebRequest.RequestMatcher;
 var CancelRequest = chrome.declarativeWebRequest.CancelRequest;
 var RedirectRequest = chrome.declarativeWebRequest.RedirectRequest;
@@ -14,6 +16,8 @@ var SetRequestHeader =
     chrome.declarativeWebRequest.SetRequestHeader;
 var RemoveRequestHeader =
     chrome.declarativeWebRequest.RemoveRequestHeader;
+var RemoveResponseHeader =
+    chrome.declarativeWebRequest.RemoveResponseHeader;
 var IgnoreRules =
     chrome.declarativeWebRequest.IgnoreRules;
 
@@ -36,6 +40,10 @@ function getURLHttpRedirectTest() {
       "files/extensions/api_test/webrequest/declarative/a.html");
 }
 
+function getURLSetCookie() {
+  return getServerURL('set-cookie?Foo=Bar');
+}
+
 runTests([
   function testCancelRequest() {
     ignoreUnexpected = true;
@@ -222,6 +230,49 @@ runTests([
       });
   },
 
+  function testAddResponseHeader() {
+    ignoreUnexpected = true;
+    expect();  // Used for initialization.
+    onRequest.addRules(
+      [{conditions: [new RequestMatcher()],
+        actions: [new AddResponseHeader({name: "Set-Cookie", value: "Bar=baz"})]
+       }],
+      function() {
+        navigateAndWait(getURLEchoUserAgent(), function() {
+          chrome.test.listenOnce(chrome.extension.onRequest, function(request) {
+            chrome.test.assertTrue(request.pass, "Cookie was not added.");
+          });
+          chrome.tabs.executeScript(tabId,
+            {
+              code: "chrome.extension.sendRequest(" +
+                    "{pass: document.cookie.indexOf('Bar') != -1});"
+            });
+        });
+      });
+  },
+
+  function testRemoveResponseHeader() {
+    ignoreUnexpected = true;
+    expect();  // Used for initialization.
+    onRequest.addRules(
+      [{conditions: [new RequestMatcher()],
+        actions: [new RemoveResponseHeader({name: "Set-Cookie",
+                                            value: "FoO=bAR"})]
+       }],
+      function() {
+        navigateAndWait(getURLSetCookie(), function() {
+          chrome.test.listenOnce(chrome.extension.onRequest, function(request) {
+            chrome.test.assertTrue(request.pass, "Cookie was not removed.");
+          });
+          chrome.tabs.executeScript(tabId,
+            {
+              code: "chrome.extension.sendRequest(" +
+                    "{pass: document.cookie.indexOf('Foo') == -1});"
+            });
+        });
+      });
+  },
+
   function testPriorities() {
     ignoreUnexpected = true;
     expect(