Remove content::BrowserThread knowledge from Device Sensors

content/browser/device_sensors/device_sensor_service.cc

Index: content/browser/device_sensors/device_sensor_service.cc
diff --git a/content/browser/device_sensors/device_sensor_service.cc b/content/browser/device_sensors/device_sensor_service.cc
index 827600740f7c4bf3355020a3fbe8c85e782f53ee..b058af81f9d786adc6461ff661e5cba3f03d8782 100644
--- a/content/browser/device_sensors/device_sensor_service.cc
+++ b/content/browser/device_sensors/device_sensor_service.cc
@@ -7,8 +7,13 @@
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/memory/singleton.h"
+#include "build/build_config.h"
 #include "content/browser/device_sensors/data_fetcher_shared_memory.h"
 
+#if defined(OS_ANDROID)
+#include "content/browser/device_sensors/sensor_manager_android.h"
+#endif
+
 namespace content {
 
 DeviceSensorService::DeviceSensorService()
@@ -46,7 +51,7 @@ void DeviceSensorService::RemoveConsumer(ConsumerType consumer_type) {
 
 bool DeviceSensorService::ChangeNumberConsumers(ConsumerType consumer_type,
                                                 int delta) {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(io_thread_checker_.CalledOnValidThread());
   if (is_shutdown_)
     return false;
 
@@ -91,13 +96,26 @@ int DeviceSensorService::GetNumberConsumers(ConsumerType consumer_type) const {
 
 mojo::ScopedSharedBufferHandle DeviceSensorService::GetSharedMemoryHandle(
     ConsumerType consumer_type) {
-  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(io_thread_checker_.CalledOnValidThread());
   return data_fetcher_->GetSharedMemoryHandle(consumer_type);
 }
 
-void DeviceSensorService::Shutdown() {
+void DeviceSensorService::InitOnUIThread() {
+#if defined(OS_ANDROID)
+  SensorManagerAndroid::GetInstance()->InitOnUIThread();
+#endif
+}
+
+void DeviceSensorService::InitOnIOThread() {

[timvolodine, 2016/10/12 16:28:58]

I am slightly confused by the two Init methods, with the first only doing
something for android, while the second seems a bit 'hacky'. Is there a way to
limit the change to android (and drop the InitOnIOThread/UIThread)?

A few ideas: maybe by either putting the ifdef block in InitOnUIThread in
browser_main_loop.cc directly.. or maybe even better to let the mojo IPC arrive
on UI thread for android and set the taskrunner there since most android calls
happen on UI anyway. That way we avoid the overhead of constructing
sensor_manager_android and its java counterpart on each startup. wdyt?

+  // Ensure that the thread checker is associated with the IO thread in case
+  // instantiation of this object occurred on the UI thread.
+  io_thread_checker_.DetachFromThread();
+  ignore_result(io_thread_checker_.CalledOnValidThread());
+}
+
+void DeviceSensorService::ShutDownOnUIThread() {
   if (data_fetcher_) {
-    data_fetcher_->Shutdown();
+    data_fetcher_->ShutDownOnUIThread();
     data_fetcher_.reset();
   }
   is_shutdown_ = true;
@@ -106,7 +124,7 @@ void DeviceSensorService::Shutdown() {
 void DeviceSensorService::SetDataFetcherForTesting(
     DataFetcherSharedMemory* test_data_fetcher) {
   if (data_fetcher_)
-    data_fetcher_->Shutdown();
+    data_fetcher_->ShutDownOnUIThread();
   data_fetcher_.reset(test_data_fetcher);
 }