Componentize component_updater: Split content::ResourceThrottle from CUS.

BUG=371463

Review URL: https://codereview.chromium.org/421393002

Cr-Commit-Position: refs/heads/master@{#288367}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288367 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/component_updater/component_updater_resource_throttle.cc

+// Copyright 2014 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/component_updater/component_updater_resource_throttle.h"
+
+#include "base/location.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/component_updater/component_updater_service.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/resource_controller.h"
+#include "content/public/browser/resource_throttle.h"
+
+using content::BrowserThread;
+
+namespace component_updater {
+
+namespace {
+
+///////////////////////////////////////////////////////////////////////////////
+// In charge of blocking url requests until the |crx_id| component has been
+// updated. This class is touched solely from the IO thread. The UI thread
+// can post tasks to it via weak pointers. By default the request is blocked
+// unless the CrxUpdateService calls Unblock().
+// The lifetime is controlled by Chrome's resource loader so the component
+// updater cannot touch objects from this class except via weak pointers.
+class CUResourceThrottle : public content::ResourceThrottle,
+                           public base::SupportsWeakPtr<CUResourceThrottle> {
+ public:
+  CUResourceThrottle();
+  virtual ~CUResourceThrottle();
+
+  // Overriden from ResourceThrottle.
+  virtual void WillStartRequest(bool* defer) OVERRIDE;
+  virtual void WillRedirectRequest(const GURL& new_url, bool* defer) OVERRIDE;
+  virtual const char* GetNameForLogging() const OVERRIDE;
+
+  // Component updater calls this function via PostTask to unblock the request.
+  void Unblock();
+
+  typedef std::vector<base::WeakPtr<CUResourceThrottle> > WeakPtrVector;
+
+ private:
+  enum State { NEW, BLOCKED, UNBLOCKED };
+
+  State state_;
+};
+
+CUResourceThrottle::CUResourceThrottle() : state_(NEW) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+}
+
+CUResourceThrottle::~CUResourceThrottle() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+}
+
+void CUResourceThrottle::WillStartRequest(bool* defer) {
+  if (state_ != UNBLOCKED) {
+    state_ = BLOCKED;
+    *defer = true;
+  } else {
+    *defer = false;
+  }
+}
+
+void CUResourceThrottle::WillRedirectRequest(const GURL& new_url, bool* defer) {
+  WillStartRequest(defer);
+}
+
+const char* CUResourceThrottle::GetNameForLogging() const {
+  return "ComponentUpdateResourceThrottle";
+}
+
+void CUResourceThrottle::Unblock() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  if (state_ == BLOCKED)
+    controller()->Resume();
+  state_ = UNBLOCKED;
+}
+
+void UnblockThrottleOnUIThread(base::WeakPtr<CUResourceThrottle> rt) {
+  BrowserThread::PostTask(BrowserThread::IO,
+                          FROM_HERE,
+                          base::Bind(&CUResourceThrottle::Unblock, rt));
+}
+
+}  // namespace
+
+content::ResourceThrottle* GetOnDemandResourceThrottle(
+    ComponentUpdateService* cus,
+    const std::string& crx_id) {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  // We give the raw pointer to the caller, who will delete it at will
+  // and we keep for ourselves a weak pointer to it so we can post tasks
+  // from the UI thread without having to track lifetime directly.
+  CUResourceThrottle* rt = new CUResourceThrottle;
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&ComponentUpdateService::MaybeThrottle,
+                 base::Unretained(cus),
+                 crx_id,
+                 base::Bind(&UnblockThrottleOnUIThread, rt->AsWeakPtr())));
+  return rt;
+}
+
+}  // namespace component_updater

chrome/browser/component_updater/component_updater_resource_throttle.h

+// Copyright 2014 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_COMPONENT_UPDATER_COMPONENT_UPDATER_RESOURCE_THROTTLE_H_
+#define CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_RESOURCE_THROTTLE_H_
+
+#include <string>
+
+namespace content {
+class ResourceThrottle;
+}
+
+namespace component_updater {
+
+class ComponentUpdateService;
+
+// Returns a network resource throttle. It means that a component will be
+// downloaded and installed before the resource is unthrottled. This function
+// can be called from the IO thread.
+content::ResourceThrottle* GetOnDemandResourceThrottle(
+    ComponentUpdateService* cus,
+    const std::string& crx_id);
+
+}  // namespace component_updater
+
+#endif  // CHROME_BROWSER_COMPONENT_UPDATER_COMPONENT_UPDATER_RESOURCE_THROTTLE_H_

chrome/browser/component_updater/component_updater_service.h

@@ -8,6 +8,7 @@
 #include <string>
 #include <vector>
 
+#include "base/callback_forward.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/version.h"
@@ -171,6 +172,21 @@ class ComponentUpdateService {
   // proactively triggered outside the normal component update service schedule.
   virtual OnDemandUpdater& GetOnDemandUpdater() = 0;
 
+  // This method is used to trigger an on-demand update for component |crx_id|.
+  // This can be used when loading a resource that depends on this component.
+  //
+  // |callback| is called on the main thread once the on-demand update is
+  // complete, regardless of success. |callback| may be called immediately
+  // within the method body.
+  //
+  // Additionally, this function implements an embedder-defined cooldown
+  // interval between on demand update attempts. This behavior is intended
+  // to be defensive against programming bugs, usually triggered by web fetches,
+  // where the on-demand functionality is invoked too often. If this function
+  // is called while still on cooldown, |callback| will be called immediately.
+  virtual void MaybeThrottle(const std::string& crx_id,
+                             const base::Closure& callback) = 0;
+
   // Returns a task runner suitable for use by component installers.
   virtual scoped_refptr<base::SequencedTaskRunner> GetSequencedTaskRunner() = 0;
 
@@ -183,7 +199,6 @@ class ComponentUpdateService {
                                    CrxUpdateItem* item) const = 0;
 
   friend class ::ComponentsUI;
-  FRIEND_TEST_ALL_PREFIXES(ComponentUpdaterTest, ResourceThrottleLiveNoUpdate);
 };
 
 typedef ComponentUpdateService::Observer ServiceObserver;
@@ -192,17 +207,6 @@ class OnDemandUpdater {
  public:
   virtual ~OnDemandUpdater() {}
 
-  // Returns a network resource throttle. It means that a component will be
-  // downloaded and installed before the resource is unthrottled. This function
-  // can be called from the IO thread. The function implements a cooldown
-  // interval of 30 minutes. That means it will ineffective to call the
-  // function before the cooldown interval has passed. This behavior is intended
-  // to be defensive against programming bugs, usually triggered by web fetches,
-  // where the on-demand functionality is invoked too often.
-  virtual content::ResourceThrottle* GetOnDemandResourceThrottle(
-      net::URLRequest* request,
-      const std::string& crx_id) = 0;
-
  private:
   friend class OnDemandTester;
   friend class ::ComponentsUI;

chrome/browser/component_updater/crx_update_item.h

@@ -17,8 +17,6 @@
 
 namespace component_updater {
 
-class CUResourceThrottle;
-
 // This is the one and only per-item state structure. Designed to be hosted
 // in a std::vector or a std::list. The two main members are |component|
 // which is supplied by the the component updater client and |status| which
@@ -110,7 +108,7 @@ struct CrxUpdateItem {
 
   std::vector<CrxDownloader::DownloadMetrics> download_metrics;
 
-  std::vector<base::WeakPtr<CUResourceThrottle> > throttles;
+  std::vector<base::Closure> ready_callbacks;
 
   CrxUpdateItem();
   ~CrxUpdateItem();

chrome/browser/component_updater/test/component_updater_service_unittest.cc

@@ -12,6 +12,7 @@
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/values.h"
+#include "chrome/browser/component_updater/component_updater_resource_throttle.h"
 #include "chrome/browser/component_updater/component_updater_utils.h"
 #include "chrome/browser/component_updater/test/test_configurator.h"
 #include "chrome/browser/component_updater/test/test_installer.h"
@@ -1190,9 +1191,7 @@ content::ResourceThrottle* RequestTestResourceThrottle(
                                   NULL,
                                   &context);
 
-  content::ResourceThrottle* rt =
-      cus->GetOnDemandUpdater().GetOnDemandResourceThrottle(&url_request,
-                                                            crx_id);
+  content::ResourceThrottle* rt = GetOnDemandResourceThrottle(cus, crx_id);
   rt->set_controller_for_testing(controller);
   controller->SetThrottle(rt);
   return rt;

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc

@@ -12,7 +12,7 @@
 #include "base/logging.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
-#include "chrome/browser/component_updater/component_updater_service.h"
+#include "chrome/browser/component_updater/component_updater_resource_throttle.h"
 #include "chrome/browser/component_updater/pnacl/pnacl_component_installer.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
 #include "chrome/browser/download/download_request_limiter.h"
@@ -248,7 +248,7 @@ void AppendComponentUpdaterThrottles(
     // We got a component we need to install, so throttle the resource
     // until the component is installed.
     throttles->push_back(
-        cus->GetOnDemandUpdater().GetOnDemandResourceThrottle(request, crx_id));
+        component_updater::GetOnDemandResourceThrottle(cus, crx_id));
   }
 }
 

chrome/chrome_browser.gypi

@@ -279,6 +279,8 @@
       'browser/component_updater/component_unpacker.h',
       'browser/component_updater/component_updater_ping_manager.cc',
       'browser/component_updater/component_updater_ping_manager.h',
+      'browser/component_updater/component_updater_resource_throttle.cc',
+      'browser/component_updater/component_updater_resource_throttle.h',
       'browser/component_updater/component_updater_service.cc',
       'browser/component_updater/component_updater_service.h',
       'browser/component_updater/component_updater_utils.cc',