Changes ProviderImpl to use a single DataFetcherFactory

content/browser/device_orientation/provider_impl.cc

Index: content/browser/device_orientation/provider_impl.cc
diff --git a/content/browser/device_orientation/provider_impl.cc b/content/browser/device_orientation/provider_impl.cc
index 6d3e0e620b1eca053296b1dc0bc5cb993060a7a0..cf572f3640eeea9ee6ce2306efb85c62d0f28f7d 100644
--- a/content/browser/device_orientation/provider_impl.cc
+++ b/content/browser/device_orientation/provider_impl.cc
@@ -47,7 +47,7 @@ class ProviderImpl::PollingThread : public base::Thread {
   virtual ~PollingThread();
 
   // Method for finding a suitable DataFetcher and starting the polling.
-  void Initialize(const std::vector<DataFetcherFactory>& factories);
+  void Initialize(const DataFetcherFactory* factory);
 
  private:
   // Method for polling a DataFetcher.
@@ -87,13 +87,13 @@ ProviderImpl::PollingThread::~PollingThread() {
 }
 
 void ProviderImpl::PollingThread::Initialize(
-    const std::vector<DataFetcherFactory>& factories) {
+    const DataFetcherFactory* factory) {
   DCHECK(MessageLoop::current() == message_loop());
 
-  typedef std::vector<DataFetcherFactory>::const_iterator Iterator;
-  for (Iterator i = factories.begin(); i != factories.end(); ++i) {
-    DataFetcherFactory factory = *i;
-    scoped_ptr<DataFetcher> fetcher(factory());
+  if (factory != NULL) {

[hans, 2012/08/01 19:08:47]

i wonder if it would make the code simpler to check if factory == NULL first,
and bail out early if so

[aousterh, 2012/08/02 10:10:38]

I don't think it would really be simpler, because we need to call
ScheduleDoNotify(Orientation::Empty()) in two cases - when factory == NULL and
when factory != NULL but the fetcher can't provide Orientation data. So if we
checked for factory == NULL first and then bailed, we would have to duplicate
the call ScheduleDoNotify(Orientation::Empty()).

+    // Try to use factory to create a fetcher that can provide orientation data.
+    DataFetcherFactory data_fetcher_factory = *factory;
+    scoped_ptr<DataFetcher> fetcher(data_fetcher_factory());
     Orientation orientation;
 
     if (fetcher.get() && fetcher->GetOrientation(&orientation)) {
@@ -183,12 +183,14 @@ base::TimeDelta ProviderImpl::PollingThread::SamplingInterval() const {
   return base::TimeDelta::FromMilliseconds(kDesiredSamplingIntervalMs);
 }
 
-ProviderImpl::ProviderImpl(const DataFetcherFactory factories[])
+ProviderImpl::ProviderImpl(const DataFetcherFactory* factory)
     : creator_loop_(MessageLoop::current()),
       ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)),
       polling_thread_(NULL) {
-  for (const DataFetcherFactory* fp = factories; *fp; ++fp)
-    factories_.push_back(*fp);
+  if (factory == NULL)
+    factory_ = NULL;
+  else
+    factory_ = new DataFetcherFactory(*factory);

[hans, 2012/08/01 19:08:47]

this looks overly complex; i think it should just boil down to factory_ =
factory

[aousterh, 2012/08/02 10:10:38]

Done.

 }
 
 ProviderImpl::~ProviderImpl() {
@@ -251,7 +253,7 @@ void ProviderImpl::ScheduleInitializePollingThread() {
   polling_loop->PostTask(FROM_HERE,
                          base::Bind(&PollingThread::Initialize,
                                     base::Unretained(polling_thread_),
-                                    factories_));
+                                    factory_));
 }
 
 void ProviderImpl::DoNotify(const Orientation& orientation) {