Implement Android shared memory data fetcher for Device Motion.

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 25e9bfd968769567b7a1d51b61e30e41634c15a9..b57819993d3eb352c7466c0e281fd66fc880b3ee 100644
--- a/content/browser/device_orientation/provider_impl.cc
+++ b/content/browser/device_orientation/provider_impl.cc
@@ -13,6 +13,12 @@
 #include "base/threading/thread.h"
 #include "base/threading/worker_pool.h"
 
+#if defined(OS_ANDROID)
+#include "content/browser/device_orientation/data_fetcher_impl_android.h"
+#elif defined(OS_WIN)
+#include "content/browser/device_orientation/data_fetcher_impl_win.h"
+#endif
+
 namespace {
 
 void DeleteThread(base::Thread* thread) {
@@ -54,7 +60,8 @@ class ProviderImpl::PollingThread : public base::Thread {
   // Typically the I/O loop, but may be something else during testing.
   base::MessageLoop* creator_loop_;
 
-  scoped_ptr<DataFetcher> data_fetcher_;
+  DataFetcher* data_fetcher_;
+
   std::map<DeviceData::Type, scoped_refptr<const DeviceData> >
     last_device_data_map_;
   std::set<DeviceData::Type> polling_data_types_;
@@ -68,6 +75,12 @@ ProviderImpl::PollingThread::PollingThread(const char* name,
     : base::Thread(name), creator_loop_(creator_loop), provider_(provider) {}
 
 ProviderImpl::PollingThread::~PollingThread() {
+#if defined(OS_ANDROID)

[bulach, 2013/07/10 16:59:41]

// TODO(timvolodine): Remove this platform dependency once
// orientation also switches to shared memory implementation.

[timvolodine, 2013/07/11 14:31:34]

N/A anymore.
Done.

+  static_cast<DataFetcherImplAndroid*>(data_fetcher_)->Stop(
+      DeviceData::kTypeOrientation);
+#elif defined(OS_WIN)
+  static_cast<DataFetcherImplWin*>(data_fetcher_)->Stop();
+#endif
   Stop();
 }
 
@@ -85,13 +98,13 @@ void ProviderImpl::PollingThread::Initialize(DataFetcherFactory factory,
     // Try to use factory to create a fetcher that can provide this type of
     // data. If factory creates a fetcher that provides this type of data,
     // start polling.
-    scoped_ptr<DataFetcher> fetcher(factory());
+    DataFetcher* fetcher = factory();

[bulach, 2013/07/10 16:59:41]

hmm... factory() normally means it'll create an object, and the caller takes
ownership.. in this case, it'd be better as something like
GetFetcherInstance()... all Fetchers would have to change, since their "Create"
methods and this factory don't make much sense anymore...

however, thinking more about this:
it seems we're completely changing the ownership model of the fetcher.
it'd probably be better to do all of that in a separate patch, then this one can
focus only on implementing the Android data fetcher... wdyt?

[timvolodine, 2013/07/11 14:31:34]

Sure. I've refactored the code and added a new class for handling the device
orientation implementation in a transparent way, as discussed yesterday. The
other fetchers and the device orientation provider do not have to change in this
case.

 
     if (fetcher) {
       scoped_refptr<const DeviceData> device_data(fetcher->GetDeviceData(type));
       if (device_data.get() != NULL) {
         // Pass ownership of fetcher to provider_.

[bulach, 2013/07/10 16:59:41]

remove comment?

[timvolodine, 2013/07/11 14:31:34]

N/A anymore.
Done.

-        data_fetcher_.swap(fetcher);
+        data_fetcher_ = fetcher;
         last_device_data_map_[type] = device_data;
 
         // Notify observers.
@@ -158,7 +171,7 @@ void ProviderImpl::PollingThread::ScheduleDoPoll() {
 
 base::TimeDelta ProviderImpl::PollingThread::SamplingInterval() const {
   DCHECK(base::MessageLoop::current() == message_loop());
-  DCHECK(data_fetcher_.get());
+  DCHECK(data_fetcher_);
 
   // TODO(erg): There used to be unused code here, that called a default
   // implementation on the DataFetcherInterface that was never defined. I'm