Revert 288017 "Parse Drive API responses all at once in the bloc..."

It broke Drive sync completely.

> Parse Drive API responses all at once in the blocking pool.
> 
> Previous implementation did the parsing of string to base::Value
> on blocking pool, and that of base::Value to specific data types
> either on UI thread or on yet another post to blocking pool.
> 
> The previous implementation is slightly inefficient and moreover
> involves a subtle bug 284244.
> 
> BUG=284244
> 
> Review URL: https://codereview.chromium.org/442193002

TBR=kinaba@chromium.org
BUG=401843

Review URL: https://codereview.chromium.org/449323002

Cr-Commit-Position: refs/heads/master@{#288216}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288216 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/drive/drive_api_service.cc

@@ -8,7 +8,10 @@
 #include <vector>
 
 #include "base/bind.h"
+#include "base/sequenced_task_runner.h"
 #include "base/strings/stringprintf.h"
+#include "base/task_runner_util.h"
+#include "base/values.h"
 #include "chrome/browser/drive/drive_api_util.h"
 #include "content/public/browser/browser_thread.h"
 #include "google_apis/drive/auth_service.h"
@@ -146,16 +149,6 @@ void ExtractOpenUrlAndRun(const std::string& app_id,
   callback.Run(GDATA_OTHER_ERROR, GURL());
 }
 
-void ExtractShareUrlAndRun(const google_apis::GetShareUrlCallback& callback,
-                           google_apis::GDataErrorCode error,
-                           scoped_ptr<google_apis::ResourceEntry> entry) {
-  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
-
-  const google_apis::Link* share_link =
-      entry ? entry->GetLinkByType(google_apis::Link::LINK_SHARE) : NULL;
-  callback.Run(error, share_link ? share_link->href() : GURL());
-}
-
 // Ignores the |entry|, and runs the |callback|.
 void EntryActionCallbackAdapter(
     const EntryActionCallback& callback,
@@ -383,7 +376,7 @@ CancelCallback DriveAPIService::GetShareUrl(
                                   wapi_url_generator_,
                                   resource_id,
                                   embed_origin,
-                                  base::Bind(&ExtractShareUrlAndRun,
+                                  base::Bind(&util::ParseShareUrlAndRun,
                                              callback)));
 }
 

chrome/browser/drive/drive_api_util.cc

@@ -136,6 +136,29 @@ std::string CanonicalizeResourceId(const std::string& resource_id) {
   return resource_id;
 }
 
+void ParseShareUrlAndRun(const google_apis::GetShareUrlCallback& callback,
+                         google_apis::GDataErrorCode error,
+                         scoped_ptr<base::Value> value) {
+  DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
+  if (!value) {
+    callback.Run(error, GURL());
+    return;
+  }
+
+  // Parsing ResourceEntry is cheap enough to do on UI thread.
+  scoped_ptr<google_apis::ResourceEntry> entry =
+      google_apis::ResourceEntry::ExtractAndParse(*value);
+  if (!entry) {
+    callback.Run(google_apis::GDATA_PARSE_ERROR, GURL());
+    return;
+  }
+
+  const google_apis::Link* share_link =
+      entry->GetLinkByType(google_apis::Link::LINK_SHARE);
+  callback.Run(error, share_link ? share_link->href() : GURL());
+}
+
 scoped_ptr<google_apis::ResourceEntry>
 ConvertFileResourceToResourceEntry(
     const google_apis::FileResource& file_resource) {

chrome/browser/drive/drive_api_util.h

@@ -63,6 +63,12 @@ std::string ExtractResourceIdFromUrl(const GURL& url);
 // into the new format.
 std::string CanonicalizeResourceId(const std::string& resource_id);
 
+// Extracts an url to the sharing dialog and returns it via |callback|. If
+// the share url doesn't exist, then an empty url is returned.
+void ParseShareUrlAndRun(const google_apis::GetShareUrlCallback& callback,
+                         google_apis::GDataErrorCode error,
+                         scoped_ptr<base::Value> value);
+
 // Converts FileResource to ResourceEntry.
 scoped_ptr<google_apis::ResourceEntry>
 ConvertFileResourceToResourceEntry(

google_apis/drive/base_requests.cc

@@ -43,18 +43,29 @@ const char kUploadResponseLocation[] = "location";
 const char kUploadContentRange[] = "Content-Range: bytes ";
 const char kUploadResponseRange[] = "range";
 
-// Parses JSON passed in |json| on |blocking_task_runner|. Runs |callback| on
-// the calling thread when finished with either success or failure.
-// The callback must not be null.
-void ParseJsonOnBlockingPool(
-    base::TaskRunner* blocking_task_runner,
-    const std::string& json,
-    const base::Callback<void(scoped_ptr<base::Value> value)>& callback) {
-  base::PostTaskAndReplyWithResult(
-      blocking_task_runner,
-      FROM_HERE,
-      base::Bind(&google_apis::ParseJson, json),
-      callback);
+// Parse JSON string to base::Value object.
+scoped_ptr<base::Value> ParseJsonInternal(const std::string& json) {
+  int error_code = -1;
+  std::string error_message;
+  scoped_ptr<base::Value> value(base::JSONReader::ReadAndReturnError(
+      json, base::JSON_PARSE_RFC, &error_code, &error_message));
+
+  if (!value.get()) {
+    std::string trimmed_json;
+    if (json.size() < 80) {
+      trimmed_json  = json;
+    } else {
+      // Take the first 50 and the last 10 bytes.
+      trimmed_json = base::StringPrintf(
+          "%s [%s bytes] %s",
+          json.substr(0, 50).c_str(),
+          base::Uint64ToString(json.size() - 60).c_str(),
+          json.substr(json.size() - 10).c_str());
+    }
+    LOG(WARNING) << "Error while parsing entry response: " << error_message
+                 << ", code: " << error_code << ", json:\n" << trimmed_json;
+  }
+  return value.Pass();
 }
 
 // Returns response headers as a string. Returns a warning message if
@@ -84,28 +95,14 @@ bool IsSuccessfulResponseCode(int response_code) {
 
 namespace google_apis {
 
-scoped_ptr<base::Value> ParseJson(const std::string& json) {
-  int error_code = -1;
-  std::string error_message;
-  scoped_ptr<base::Value> value(base::JSONReader::ReadAndReturnError(
-      json, base::JSON_PARSE_RFC, &error_code, &error_message));
-
-  if (!value.get()) {
-    std::string trimmed_json;
-    if (json.size() < 80) {
-      trimmed_json  = json;
-    } else {
-      // Take the first 50 and the last 10 bytes.
-      trimmed_json = base::StringPrintf(
-          "%s [%s bytes] %s",
-          json.substr(0, 50).c_str(),
-          base::Uint64ToString(json.size() - 60).c_str(),
-          json.substr(json.size() - 10).c_str());
-    }
-    LOG(WARNING) << "Error while parsing entry response: " << error_message
-                 << ", code: " << error_code << ", json:\n" << trimmed_json;
-  }
-  return value.Pass();
+void ParseJson(base::TaskRunner* blocking_task_runner,
+               const std::string& json,
+               const ParseJsonCallback& callback) {
+  base::PostTaskAndReplyWithResult(
+      blocking_task_runner,
+      FROM_HERE,
+      base::Bind(&ParseJsonInternal, json),
+      callback);
 }
 
 //=========================== ResponseWriter ==================================
@@ -362,7 +359,7 @@ void UrlFetchRequestBase::OnURLFetchComplete(const URLFetcher* source) {
     const char kErrorReasonUserRateLimitExceeded[] = "userRateLimitExceeded";
     const char kErrorReasonQuotaExceeded[] = "quotaExceeded";
 
-    scoped_ptr<base::Value> value(ParseJson(response_writer_->data()));
+    scoped_ptr<base::Value> value(ParseJsonInternal(response_writer_->data()));
     base::DictionaryValue* dictionary = NULL;
     base::DictionaryValue* error = NULL;
     if (value &&
@@ -437,6 +434,62 @@ void EntryActionRequest::RunCallbackOnPrematureFailure(GDataErrorCode code) {
   callback_.Run(code);
 }
 
+//============================== GetDataRequest ==============================
+
+GetDataRequest::GetDataRequest(RequestSender* sender,
+                               const GetDataCallback& callback)
+    : UrlFetchRequestBase(sender),
+      callback_(callback),
+      weak_ptr_factory_(this) {
+  DCHECK(!callback_.is_null());
+}
+
+GetDataRequest::~GetDataRequest() {}
+
+void GetDataRequest::ParseResponse(GDataErrorCode fetch_error_code,
+                                   const std::string& data) {
+  DCHECK(CalledOnValidThread());
+
+  VLOG(1) << "JSON received from " << GetURL().spec() << ": "
+          << data.size() << " bytes";
+  ParseJson(blocking_task_runner(),
+            data,
+            base::Bind(&GetDataRequest::OnDataParsed,
+                       weak_ptr_factory_.GetWeakPtr(),
+                       fetch_error_code));
+}
+
+void GetDataRequest::ProcessURLFetchResults(const URLFetcher* source) {
+  GDataErrorCode fetch_error_code = GetErrorCode();
+
+  switch (fetch_error_code) {
+    case HTTP_SUCCESS:
+    case HTTP_CREATED:
+      ParseResponse(fetch_error_code, response_writer()->data());
+      break;
+    default:
+      RunCallbackOnPrematureFailure(fetch_error_code);
+      OnProcessURLFetchResultsComplete();
+      break;
+  }
+}
+
+void GetDataRequest::RunCallbackOnPrematureFailure(
+    GDataErrorCode fetch_error_code) {
+  callback_.Run(fetch_error_code, scoped_ptr<base::Value>());
+}
+
+void GetDataRequest::OnDataParsed(GDataErrorCode fetch_error_code,
+                                  scoped_ptr<base::Value> value) {
+  DCHECK(CalledOnValidThread());
+
+  if (!value.get())
+    fetch_error_code = GDATA_PARSE_ERROR;
+
+  callback_.Run(fetch_error_code, value.Pass());
+  OnProcessURLFetchResultsComplete();
+}
+
 //========================= InitiateUploadRequestBase ========================
 
 InitiateUploadRequestBase::InitiateUploadRequestBase(
@@ -565,11 +618,11 @@ void UploadRangeRequestBase::ProcessURLFetchResults(
   } else if (code == HTTP_CREATED || code == HTTP_SUCCESS) {
     // The upload is successfully done. Parse the response which should be
     // the entry's metadata.
-    ParseJsonOnBlockingPool(blocking_task_runner(),
-                            response_writer()->data(),
-                            base::Bind(&UploadRangeRequestBase::OnDataParsed,
-                                       weak_ptr_factory_.GetWeakPtr(),
-                                       code));
+    ParseJson(blocking_task_runner(),
+              response_writer()->data(),
+              base::Bind(&UploadRangeRequestBase::OnDataParsed,
+                         weak_ptr_factory_.GetWeakPtr(),
+                         code));
   } else {
     // Failed to upload. Run callbacks to notify the error.
     OnRangeRequestComplete(

google_apis/drive/base_requests.h

@@ -29,6 +29,10 @@ namespace google_apis {
 
 class RequestSender;
 
+// Callback used to pass parsed JSON from ParseJson(). If parsing error occurs,
+// then the passed argument is null.
+typedef base::Callback<void(scoped_ptr<base::Value> value)> ParseJsonCallback;
+
 // Callback used for DownloadFileRequest and ResumeUploadRequestBase.
 typedef base::Callback<void(int64 progress, int64 total)> ProgressCallback;
 
@@ -37,8 +41,12 @@ typedef base::Callback<void(
     GDataErrorCode error,
     scoped_ptr<std::string> content)> GetContentCallback;
 
-// Parses JSON passed in |json|. Returns NULL on failure.
-scoped_ptr<base::Value> ParseJson(const std::string& json);
+// Parses JSON passed in |json| on |blocking_task_runner|. Runs |callback| on
+// the calling thread when finished with either success or failure.
+// The callback must not be null.
+void ParseJson(base::TaskRunner* blocking_task_runner,
+               const std::string& json,
+               const ParseJsonCallback& callback);
 
 //======================= AuthenticatedRequestInterface ======================
 
@@ -241,6 +249,45 @@ class EntryActionRequest : public UrlFetchRequestBase {
   DISALLOW_COPY_AND_ASSIGN(EntryActionRequest);
 };
 
+//============================== GetDataRequest ==============================
+
+// Callback type for requests that returns JSON data.
+typedef base::Callback<void(GDataErrorCode error,
+                            scoped_ptr<base::Value> json_data)> GetDataCallback;
+
+// This class performs the request for fetching and converting the fetched
+// content into a base::Value.
+class GetDataRequest : public UrlFetchRequestBase {
+ public:
+  // |callback| is called when the request finishes either by success or by
+  // failure. On success, a JSON Value object is passed. It must not be null.
+  GetDataRequest(RequestSender* sender, const GetDataCallback& callback);
+  virtual ~GetDataRequest();
+
+ protected:
+  // UrlFetchRequestBase overrides.
+  virtual void ProcessURLFetchResults(const net::URLFetcher* source) OVERRIDE;
+  virtual void RunCallbackOnPrematureFailure(
+      GDataErrorCode fetch_error_code) OVERRIDE;
+
+ private:
+  // Parses JSON response.
+  void ParseResponse(GDataErrorCode fetch_error_code, const std::string& data);
+
+  // Called when ParseJsonOnBlockingPool() is completed.
+  void OnDataParsed(GDataErrorCode fetch_error_code,
+                    scoped_ptr<base::Value> value);
+
+  const GetDataCallback callback_;
+
+  // Note: This should remain the last member so it'll be destroyed and
+  // invalidate its weak pointers before any other members are destroyed.
+  base::WeakPtrFactory<GetDataRequest> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(GetDataRequest);
+};
+
+
 //=========================== InitiateUploadRequestBase=======================
 
 // Callback type for DriveServiceInterface::InitiateUpload.

google_apis/drive/base_requests_unittest.cc

@@ -51,6 +51,24 @@ class FakeUrlFetchRequest : public UrlFetchRequestBase {
   GURL url_;
 };
 
+class FakeGetDataRequest : public GetDataRequest {
+ public:
+  explicit FakeGetDataRequest(RequestSender* sender,
+                              const GetDataCallback& callback,
+                              const GURL& url)
+      : GetDataRequest(sender, callback),
+        url_(url) {
+  }
+
+  virtual ~FakeGetDataRequest() {
+  }
+
+ protected:
+  virtual GURL GetURL() const OVERRIDE { return url_; }
+
+  GURL url_;
+};
+
 }  // namespace
 
 class BaseRequestsTest : public testing::Test {
@@ -91,7 +109,11 @@ class BaseRequestsTest : public testing::Test {
 };
 
 TEST_F(BaseRequestsTest, ParseValidJson) {
-  scoped_ptr<base::Value> json(ParseJson(kValidJsonString));
+  scoped_ptr<base::Value> json;
+  ParseJson(message_loop_.message_loop_proxy(),
+            kValidJsonString,
+            base::Bind(test_util::CreateCopyResultCallback(&json)));
+  base::RunLoop().RunUntilIdle();
 
   base::DictionaryValue* root_dict = NULL;
   ASSERT_TRUE(json);
@@ -103,7 +125,14 @@ TEST_F(BaseRequestsTest, ParseValidJson) {
 }
 
 TEST_F(BaseRequestsTest, ParseInvalidJson) {
-  EXPECT_FALSE(ParseJson(kInvalidJsonString));
+  // Initialize with a valid pointer to verify that null is indeed assigned.
+  scoped_ptr<base::Value> json(base::Value::CreateNullValue());
+  ParseJson(message_loop_.message_loop_proxy(),
+            kInvalidJsonString,
+            base::Bind(test_util::CreateCopyResultCallback(&json)));
+  base::RunLoop().RunUntilIdle();
+
+  EXPECT_FALSE(json);
 }
 
 TEST_F(BaseRequestsTest, UrlFetchRequestBaseResponseCodeOverride) {
@@ -136,4 +165,40 @@ TEST_F(BaseRequestsTest, UrlFetchRequestBaseResponseCodeOverride) {
   EXPECT_EQ(HTTP_SERVICE_UNAVAILABLE, error);
 }
 
+TEST_F(BaseRequestsTest, GetDataRequestParseValidResponse) {
+  response_body_ = kValidJsonString;
+
+  GDataErrorCode error = GDATA_OTHER_ERROR;
+  scoped_ptr<base::Value> value;
+  base::RunLoop run_loop;
+  sender_->StartRequestWithRetry(
+      new FakeGetDataRequest(
+          sender_.get(),
+          test_util::CreateQuitCallback(
+              &run_loop, test_util::CreateCopyResultCallback(&error, &value)),
+          test_server_.base_url()));
+  run_loop.Run();
+
+  EXPECT_EQ(HTTP_SUCCESS, error);
+  EXPECT_TRUE(value);
+}
+
+TEST_F(BaseRequestsTest, GetDataRequestParseInvalidResponse) {
+  response_body_ = kInvalidJsonString;
+
+  GDataErrorCode error = GDATA_OTHER_ERROR;
+  scoped_ptr<base::Value> value;
+  base::RunLoop run_loop;
+  sender_->StartRequestWithRetry(
+      new FakeGetDataRequest(
+          sender_.get(),
+          test_util::CreateQuitCallback(
+              &run_loop, test_util::CreateCopyResultCallback(&error, &value)),
+          test_server_.base_url()));
+  run_loop.Run();
+
+  EXPECT_EQ(GDATA_PARSE_ERROR, error);
+  EXPECT_FALSE(value);
+}
+
 }  // namespace google_apis

google_apis/drive/drive_api_requests.cc

@@ -11,6 +11,7 @@
 #include "base/sequenced_task_runner.h"
 #include "base/task_runner_util.h"
 #include "base/values.h"
+#include "google_apis/drive/drive_api_parser.h"
 #include "google_apis/drive/request_sender.h"
 #include "google_apis/drive/request_util.h"
 #include "google_apis/drive/time_util.h"
@@ -22,6 +23,70 @@ namespace {
 const char kContentTypeApplicationJson[] = "application/json";
 const char kParentLinkKind[] = "drive#fileLink";
 
+// Parses the JSON value to a resource typed |T| and runs |callback| on the UI
+// thread once parsing is done.
+template<typename T>
+void ParseJsonAndRun(
+    const base::Callback<void(GDataErrorCode, scoped_ptr<T>)>& callback,
+    GDataErrorCode error,
+    scoped_ptr<base::Value> value) {
+  DCHECK(!callback.is_null());
+
+  scoped_ptr<T> resource;
+  if (value) {
+    resource = T::CreateFrom(*value);
+    if (!resource) {
+      // Failed to parse the JSON value, although the JSON value is available,
+      // so let the callback know the parsing error.
+      error = GDATA_PARSE_ERROR;
+    }
+  }
+
+  callback.Run(error, resource.Pass());
+}
+
+// Thin adapter of T::CreateFrom.
+template<typename T>
+scoped_ptr<T> ParseJsonOnBlockingPool(scoped_ptr<base::Value> value) {
+  return T::CreateFrom(*value);
+}
+
+// Runs |callback| with given |error| and |value|. If |value| is null,
+// overwrites |error| to GDATA_PARSE_ERROR.
+template<typename T>
+void ParseJsonOnBlockingPoolAndRunAfterBlockingPoolTask(
+    const base::Callback<void(GDataErrorCode, scoped_ptr<T>)>& callback,
+    GDataErrorCode error, scoped_ptr<T> value) {
+  if (!value)
+    error = GDATA_PARSE_ERROR;
+  callback.Run(error, value.Pass());
+}
+
+// Parses the JSON value to a resource typed |T| and runs |callback| on
+// blocking pool, and then run on the current thread.
+// TODO(hidehiko): Move this and ParseJsonAndRun defined above into base with
+// merging the tasks running on blocking pool into one.
+template<typename T>
+void ParseJsonOnBlockingPoolAndRun(
+    scoped_refptr<base::TaskRunner> blocking_task_runner,
+    const base::Callback<void(GDataErrorCode, scoped_ptr<T>)>& callback,
+    GDataErrorCode error,
+    scoped_ptr<base::Value> value) {
+  DCHECK(!callback.is_null());
+
+  if (!value) {
+    callback.Run(error, scoped_ptr<T>());
+    return;
+  }
+
+  base::PostTaskAndReplyWithResult(
+      blocking_task_runner,
+      FROM_HERE,
+      base::Bind(&ParseJsonOnBlockingPool<T>, base::Passed(&value)),
+      base::Bind(&ParseJsonOnBlockingPoolAndRunAfterBlockingPoolTask<T>,
+                 callback, error));
+}
+
 // Parses the JSON value to FileResource instance and runs |callback| on the
 // UI thread once parsing is done.
 // This is customized version of ParseJsonAndRun defined above to adapt the
@@ -61,16 +126,17 @@ scoped_ptr<base::DictionaryValue> CreateParentValue(
 
 namespace drive {
 
-//============================ DriveApiPartialFieldRequest ====================
+//============================ DriveApiDataRequest ===========================
 
-DriveApiPartialFieldRequest::DriveApiPartialFieldRequest(
-    RequestSender* sender) : UrlFetchRequestBase(sender) {
+DriveApiDataRequest::DriveApiDataRequest(RequestSender* sender,
+                                         const GetDataCallback& callback)
+    : GetDataRequest(sender, callback) {
 }
 
-DriveApiPartialFieldRequest::~DriveApiPartialFieldRequest() {
+DriveApiDataRequest::~DriveApiDataRequest() {
 }
 
-GURL DriveApiPartialFieldRequest::GetURL() const {
+GURL DriveApiDataRequest::GetURL() const {
   GURL url = GetURLInternal();
   if (!fields_.empty())
     url = net::AppendOrReplaceQueryParameter(url, "fields", fields_);
@@ -83,7 +149,9 @@ FilesGetRequest::FilesGetRequest(
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -100,7 +168,9 @@ FilesAuthorizeRequest::FilesAuthorizeRequest(
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -121,7 +191,9 @@ FilesInsertRequest::FilesInsertRequest(
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -178,7 +250,9 @@ FilesPatchRequest::FilesPatchRequest(
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator),
       set_modified_date_(false),
       update_viewed_date_(true) {
@@ -246,7 +320,9 @@ FilesCopyRequest::FilesCopyRequest(
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -299,7 +375,11 @@ FilesListRequest::FilesListRequest(
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileListCallback& callback)
-    : DriveApiDataRequest<FileList>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonOnBlockingPoolAndRun<FileList>,
+                     make_scoped_refptr(sender->blocking_task_runner()),
+                     callback)),
       url_generator_(url_generator),
       max_results_(100) {
   DCHECK(!callback.is_null());
@@ -316,7 +396,11 @@ GURL FilesListRequest::GetURLInternal() const {
 FilesListNextPageRequest::FilesListNextPageRequest(
     RequestSender* sender,
     const FileListCallback& callback)
-    : DriveApiDataRequest<FileList>(sender, callback) {
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonOnBlockingPoolAndRun<FileList>,
+                     make_scoped_refptr(sender->blocking_task_runner()),
+                     callback)) {
   DCHECK(!callback.is_null());
 }
 
@@ -361,7 +445,9 @@ FilesTrashRequest::FilesTrashRequest(
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const FileResourceCallback& callback)
-    : DriveApiDataRequest<FileResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<FileResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -382,7 +468,9 @@ AboutGetRequest::AboutGetRequest(
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const AboutResourceCallback& callback)
-    : DriveApiDataRequest<AboutResource>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<AboutResource>, callback)),
       url_generator_(url_generator) {
   DCHECK(!callback.is_null());
 }
@@ -399,7 +487,11 @@ ChangesListRequest::ChangesListRequest(
     RequestSender* sender,
     const DriveApiUrlGenerator& url_generator,
     const ChangeListCallback& callback)
-    : DriveApiDataRequest<ChangeList>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonOnBlockingPoolAndRun<ChangeList>,
+                     make_scoped_refptr(sender->blocking_task_runner()),
+                     callback)),
       url_generator_(url_generator),
       include_deleted_(true),
       max_results_(100),
@@ -419,7 +511,11 @@ GURL ChangesListRequest::GetURLInternal() const {
 ChangesListNextPageRequest::ChangesListNextPageRequest(
     RequestSender* sender,
     const ChangeListCallback& callback)
-    : DriveApiDataRequest<ChangeList>(sender, callback) {
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonOnBlockingPoolAndRun<ChangeList>,
+                     make_scoped_refptr(sender->blocking_task_runner()),
+                     callback)) {
   DCHECK(!callback.is_null());
 }
 
@@ -437,7 +533,9 @@ AppsListRequest::AppsListRequest(
     const DriveApiUrlGenerator& url_generator,
     bool use_internal_endpoint,
     const AppListCallback& callback)
-    : DriveApiDataRequest<AppList>(sender, callback),
+    : DriveApiDataRequest(
+          sender,
+          base::Bind(&ParseJsonAndRun<AppList>, callback)),
       url_generator_(url_generator),
       use_internal_endpoint_(use_internal_endpoint) {
   DCHECK(!callback.is_null());

google_apis/drive/gdata_wapi_requests.cc

@@ -4,37 +4,22 @@
 
 #include "google_apis/drive/gdata_wapi_requests.h"
 
-#include "base/location.h"
-#include "base/sequenced_task_runner.h"
-#include "base/task_runner_util.h"
-#include "base/values.h"
-#include "google_apis/drive/gdata_wapi_parser.h"
 #include "google_apis/drive/gdata_wapi_url_generator.h"
 
 namespace google_apis {
 
-namespace {
-
-scoped_ptr<ResourceEntry> ParseResourceEntry(const std::string& json) {
-  scoped_ptr<base::Value> value = ParseJson(json);
-  return value ? ResourceEntry::ExtractAndParse(*value) :
-      scoped_ptr<ResourceEntry>();
-}
-
-}  // namespace
+//============================ GetResourceEntryRequest =======================
 
 GetResourceEntryRequest::GetResourceEntryRequest(
     RequestSender* sender,
     const GDataWapiUrlGenerator& url_generator,
     const std::string& resource_id,
     const GURL& embed_origin,
-    const GetResourceEntryCallback& callback)
-    : UrlFetchRequestBase(sender),
+    const GetDataCallback& callback)
+    : GetDataRequest(sender, callback),
       url_generator_(url_generator),
       resource_id_(resource_id),
-      embed_origin_(embed_origin),
-      callback_(callback),
-      weak_ptr_factory_(this) {
+      embed_origin_(embed_origin) {
   DCHECK(!callback.is_null());
 }
 
@@ -45,35 +30,4 @@ GURL GetResourceEntryRequest::GetURL() const {
       resource_id_, embed_origin_);
 }
 
-void GetResourceEntryRequest::ProcessURLFetchResults(
-    const net::URLFetcher* source) {
-  GDataErrorCode error = GetErrorCode();
-  switch (error) {
-    case HTTP_SUCCESS:
-    case HTTP_CREATED:
-      base::PostTaskAndReplyWithResult(
-          blocking_task_runner(),
-          FROM_HERE,
-          base::Bind(&ParseResourceEntry, response_writer()->data()),
-          base::Bind(&GetResourceEntryRequest::OnDataParsed,
-                     weak_ptr_factory_.GetWeakPtr(), error));
-      break;
-    default:
-      RunCallbackOnPrematureFailure(error);
-      OnProcessURLFetchResultsComplete();
-      break;
-  }
-}
-
-void GetResourceEntryRequest::RunCallbackOnPrematureFailure(
-    GDataErrorCode error) {
-  callback_.Run(error, scoped_ptr<ResourceEntry>());
-}
-
-void GetResourceEntryRequest::OnDataParsed(GDataErrorCode error,
-                                           scoped_ptr<ResourceEntry> entry) {
-  callback_.Run(entry ? error : GDATA_PARSE_ERROR, entry.Pass());
-  OnProcessURLFetchResultsComplete();
-}
-
 }  // namespace google_apis

google_apis/drive/gdata_wapi_requests.h

@@ -12,44 +12,29 @@
 
 namespace google_apis {
 
-class ResourceEntry;
-
-// Callback type for GetResourceEntryRequest.
-typedef base::Callback<void(GDataErrorCode error,
-                            scoped_ptr<ResourceEntry> entry)>
-    GetResourceEntryCallback;
+//========================= GetResourceEntryRequest ==========================
 
 // This class performs the request for fetching a single resource entry.
-class GetResourceEntryRequest : public UrlFetchRequestBase {
+class GetResourceEntryRequest : public GetDataRequest {
  public:
   // |callback| must not be null.
   GetResourceEntryRequest(RequestSender* sender,
                           const GDataWapiUrlGenerator& url_generator,
                           const std::string& resource_id,
                           const GURL& embed_origin,
-                          const GetResourceEntryCallback& callback);
+                          const GetDataCallback& callback);
   virtual ~GetResourceEntryRequest();
 
  protected:
   // UrlFetchRequestBase overrides.
-  virtual void ProcessURLFetchResults(const net::URLFetcher* source) OVERRIDE;
-  virtual void RunCallbackOnPrematureFailure(GDataErrorCode error) OVERRIDE;
   virtual GURL GetURL() const OVERRIDE;
 
  private:
-  void OnDataParsed(GDataErrorCode error, scoped_ptr<ResourceEntry> entry);
-
   const GDataWapiUrlGenerator url_generator_;
   // Resource id of the requested entry.
   const std::string resource_id_;
   // Embed origin for an url to the sharing dialog. Can be empty.
-  GURL embed_origin_;
-
-  const GetResourceEntryCallback callback_;
-
-  // Note: This should remain the last member so it'll be destroyed and
-  // invalidate its weak pointers before any other members are destroyed.
-  base::WeakPtrFactory<GetResourceEntryRequest> weak_ptr_factory_;
+  const GURL& embed_origin_;
 
   DISALLOW_COPY_AND_ASSIGN(GetResourceEntryRequest);
 };

google_apis/drive/gdata_wapi_requests_unittest.cc

@@ -5,6 +5,7 @@
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/values.h"
 #include "google_apis/drive/dummy_auth_service.h"
 #include "google_apis/drive/gdata_wapi_parser.h"
 #include "google_apis/drive/gdata_wapi_requests.h"
@@ -98,7 +99,7 @@ class GDataWapiRequestsTest : public testing::Test {
 
 TEST_F(GDataWapiRequestsTest, GetResourceEntryRequest_ValidResourceId) {
   GDataErrorCode result_code = GDATA_OTHER_ERROR;
-  scoped_ptr<ResourceEntry> result_data;
+  scoped_ptr<base::Value> result_data;
 
   {
     base::RunLoop run_loop;
@@ -119,14 +120,16 @@ TEST_F(GDataWapiRequestsTest, GetResourceEntryRequest_ValidResourceId) {
   EXPECT_EQ("/feeds/default/private/full/file%3A2_file_resource_id"
             "?v=3&alt=json&showroot=true",
             http_request_.relative_url);
+  scoped_ptr<base::Value> expected_json =
+      test_util::LoadJSONFile("gdata/file_entry.json");
+  ASSERT_TRUE(expected_json);
   EXPECT_TRUE(result_data);
-  EXPECT_EQ("File 1.mp3", result_data->filename());
-  EXPECT_EQ("3b4382ebefec6e743578c76bbd0575ce", result_data->file_md5());
+  EXPECT_TRUE(base::Value::Equals(expected_json.get(), result_data.get()));
 }
 
 TEST_F(GDataWapiRequestsTest, GetResourceEntryRequest_InvalidResourceId) {
   GDataErrorCode result_code = GDATA_OTHER_ERROR;
-  scoped_ptr<ResourceEntry> result_data;
+  scoped_ptr<base::Value> result_data;
 
   {
     base::RunLoop run_loop;