Adjust URLFetcher::Create API so that object is returned as scoped_ptr.

Most interfaces were storing the object in a scoped_ptr already. This
adjusts the API so that it is a little clearer of the ownership
transfer.

A number of clients put the URLFetcher in a table and do memory
management on it themselves; this is likely templatable code
for a future CL. The scope of this CL was to change the API but
no control flow changes. Making this change found one memory leak;
(http://crbug.com/482459) has been addressed separately.

BUG=371201
TESTS=net_unittests google_api_unittests
TBR=jochen@chromium.org, thakis@chromium.org, oshima@chromium.org, armansito@chromium.org, reillyg@chromium.org, rogerta@chromium.org, stuartmorgan@chromium.org, wez@chromium.org, pavely@chromium.org, rouslan@chromium.org

Review URL: https://codereview.chromium.org/1117703002

Cr-Commit-Position: refs/heads/master@{#327901}

1 files changed, 5 insertions, 4 deletions

diff --git a/components/history/core/browser/web_history_service.cc b/components/history/core/browser/web_history_service.cc
index 91b498c..4a8b3aa 100644
--- a/components/history/core/browser/web_history_service.cc
+++ b/components/history/core/browser/web_history_service.cc
@@ -139,7 +139,7 @@ class RequestImpl : public WebHistoryService::Request,
     UMA_HISTOGRAM_BOOLEAN("WebHistory.OAuthTokenCompletion", true);
 
     // Got an access token -- start the actual API request.
-    url_fetcher_.reset(CreateUrlFetcher(access_token));
+    url_fetcher_ = CreateUrlFetcher(access_token);
     url_fetcher_->Start();
   }
 
@@ -156,11 +156,12 @@ class RequestImpl : public WebHistoryService::Request,
   }
 
   // Helper for creating a new URLFetcher for the API request.
-  net::URLFetcher* CreateUrlFetcher(const std::string& access_token) {
+  scoped_ptr<net::URLFetcher> CreateUrlFetcher(
+      const std::string& access_token) {
     net::URLFetcher::RequestType request_type = post_data_.empty() ?
         net::URLFetcher::GET : net::URLFetcher::POST;
-    net::URLFetcher* fetcher = net::URLFetcher::Create(
-        url_, request_type, this);
+    scoped_ptr<net::URLFetcher> fetcher =
+        net::URLFetcher::Create(url_, request_type, this);
     fetcher->SetRequestContext(request_context_.get());
     fetcher->SetMaxRetriesOn5xx(kMaxRetries);
     fetcher->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |