CacheStorage: Make CacheStorageContext API usable from UI thread.

In order to support moving CacheStorage off the IO thread and on to
a separate SequencedTaskRunner, we are encapsulating the threading
requirements.  This CL does this by removing the requirement that
external clients of CacheStorageContext must be on the IO thread.
Instead the API can be accessed directly on the UI thread and
CacheStorageContextImpl will handle executing the code on the correct
sequence.

Bug: 960012
Change-Id: I7d576a7deb484113cff0e9454b038f7b87c5e503
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1625971Reviewed-by: Daniel Murphy <dmurph@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Commit-Queue: Kinuko Yasuda <kinuko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#662961}

chrome/browser/browsing_data/browsing_data_cache_storage_helper.cc

@@ -25,7 +25,7 @@ namespace {
 void GetAllOriginsInfoForCacheStorageCallback(
     BrowsingDataCacheStorageHelper::FetchCallback callback,
     const std::vector<StorageUsageInfo>& origins) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(!callback.is_null());
 
   std::list<content::StorageUsageInfo> result;
@@ -35,8 +35,7 @@ void GetAllOriginsInfoForCacheStorageCallback(
     result.push_back(origin);
   }
 
-  base::PostTaskWithTraits(FROM_HERE, {BrowserThread::UI},
-                           base::BindOnce(std::move(callback), result));
+  std::move(callback).Run(result);
 }
 
 }  // namespace
@@ -52,33 +51,12 @@ BrowsingDataCacheStorageHelper::~BrowsingDataCacheStorageHelper() {}
 void BrowsingDataCacheStorageHelper::StartFetching(FetchCallback callback) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(!callback.is_null());
-  base::PostTaskWithTraits(
-      FROM_HERE, {BrowserThread::IO},
-      base::BindOnce(
-          &BrowsingDataCacheStorageHelper::FetchCacheStorageUsageInfoOnIOThread,
-          this, std::move(callback)));
-}
-
-void BrowsingDataCacheStorageHelper::DeleteCacheStorage(const GURL& origin) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-  base::PostTaskWithTraits(
-      FROM_HERE, {BrowserThread::IO},
-      base::BindOnce(
-          &BrowsingDataCacheStorageHelper::DeleteCacheStorageOnIOThread, this,
-          origin));
-}
-
-void BrowsingDataCacheStorageHelper::FetchCacheStorageUsageInfoOnIOThread(
-    FetchCallback callback) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  DCHECK(!callback.is_null());
   cache_storage_context_->GetAllOriginsInfo(base::BindOnce(
       &GetAllOriginsInfoForCacheStorageCallback, std::move(callback)));
 }
 
-void BrowsingDataCacheStorageHelper::DeleteCacheStorageOnIOThread(
-    const GURL& origin) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+void BrowsingDataCacheStorageHelper::DeleteCacheStorage(const GURL& origin) {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
   cache_storage_context_->DeleteForOrigin(origin);
 }
 

chrome/browser/browsing_data/browsing_data_cache_storage_helper.h

@@ -54,12 +54,6 @@ class BrowsingDataCacheStorageHelper
  private:
   friend class base::RefCountedThreadSafe<BrowsingDataCacheStorageHelper>;
 
-  // Deletes Cache Storages for an origin the IO thread.
-  void DeleteCacheStorageOnIOThread(const GURL& origin);
-
-  // Enumerates all Cache Storage instances on the IO thread.
-  void FetchCacheStorageUsageInfoOnIOThread(FetchCallback callback);
-
   DISALLOW_COPY_AND_ASSIGN(BrowsingDataCacheStorageHelper);
 };
 

content/browser/cache_storage/cache_storage_context_impl.cc

@@ -93,24 +93,45 @@ void CacheStorageContextImpl::SetBlobParametersForCache(
 
 void CacheStorageContextImpl::GetAllOriginsInfo(
     CacheStorageContext::GetUsageInfoCallback callback) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+  // Can be called on any sequence.
 
-  if (!cache_manager_) {
-    base::PostTaskWithTraits(
-        FROM_HERE, {BrowserThread::IO},
-        base::BindOnce(std::move(callback), std::vector<StorageUsageInfo>()));
-    return;
-  }
+  callback = base::BindOnce(
+      [](scoped_refptr<base::SequencedTaskRunner> reply_task_runner,
+         GetUsageInfoCallback inner,
+         const std::vector<StorageUsageInfo>& entries) {
+        reply_task_runner->PostTask(FROM_HERE,
+                                    base::BindOnce(std::move(inner), entries));
+      },
+      base::SequencedTaskRunnerHandle::Get(), std::move(callback));
 
-  cache_manager_->GetAllOriginsUsage(CacheStorageOwner::kCacheAPI,
-                                     std::move(callback));
+  task_runner_->PostTask(
+      FROM_HERE,
+      base::BindOnce(
+          [](scoped_refptr<CacheStorageContextImpl> context,
+             GetUsageInfoCallback callback) {
+            if (!context->cache_manager()) {
+              std::move(callback).Run(std::vector<StorageUsageInfo>());
+              return;
+            }
+            context->cache_manager()->GetAllOriginsUsage(
+                CacheStorageOwner::kCacheAPI, std::move(callback));
+          },
+          base::RetainedRef(this), std::move(callback)));
 }
 
 void CacheStorageContextImpl::DeleteForOrigin(const GURL& origin) {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-  if (cache_manager_)
-    cache_manager_->DeleteOriginData(url::Origin::Create(origin),
-                                     CacheStorageOwner::kCacheAPI);
+  // Can be called on any sequence.
+  task_runner_->PostTask(FROM_HERE,
+                         base::BindOnce(
+                             [](scoped_refptr<CacheStorageContextImpl> context,
+                                const GURL& origin) {
+                               if (!context->cache_manager())
+                                 return;
+                               context->cache_manager()->DeleteOriginData(
+                                   url::Origin::Create(origin),
+                                   CacheStorageOwner::kCacheAPI);
+                             },
+                             base::RetainedRef(this), origin));
 }
 
 void CacheStorageContextImpl::AddObserver(

content/public/browser/cache_storage_context.h

@@ -24,7 +24,7 @@ class CacheStorageContext
       base::OnceCallback<void(const std::vector<StorageUsageInfo>& usage_info)>;
 
   // Methods used in response to browsing data and quota manager requests.
-  // Must be called on the IO thread.
+  // May be called on any sequence.
   virtual void GetAllOriginsInfo(GetUsageInfoCallback callback) = 0;
   virtual void DeleteForOrigin(const GURL& origin_url) = 0;