Convert device_sensors to use mojo.

content/browser/device_sensors/data_fetcher_shared_memory_base.h

Index: content/browser/device_sensors/data_fetcher_shared_memory_base.h
diff --git a/content/browser/device_sensors/data_fetcher_shared_memory_base.h b/content/browser/device_sensors/data_fetcher_shared_memory_base.h
index f6431f82ffeb4691c1d050ec963e2c0bc1e9ca88..af125ffaf4d91d1dca331d85157b743d16740fb6 100644
--- a/content/browser/device_sensors/data_fetcher_shared_memory_base.h
+++ b/content/browser/device_sensors/data_fetcher_shared_memory_base.h
@@ -13,6 +13,7 @@
 #include "base/message_loop/message_loop.h"
 #include "content/browser/device_sensors/device_sensors_consts.h"
 #include "content/common/content_export.h"
+#include "mojo/public/cpp/system/buffer.h"
 
 namespace content {
 
@@ -36,12 +37,11 @@ class CONTENT_EXPORT DataFetcherSharedMemoryBase {
   // sensors are unregistered.
   virtual void Shutdown();
 
-  // Returns the shared memory handle of the device sensor data
-  // duplicated into the given process. This method should only be
-  // called after a call to StartFetchingDeviceData method with
+  // Returns the shared memory handle of the device sensor data. This method
+  // should only be called after a call to StartFetchingDeviceData method with
   // corresponding |consumer_type| parameter.
-  base::SharedMemoryHandle GetSharedMemoryHandleForProcess(
-      ConsumerType consumer_type, base::ProcessHandle process);
+  mojo::ScopedSharedBufferHandle GetSharedMemoryHandle(
+      ConsumerType consumer_type);
 
   enum FetcherType {
     // Fetcher runs on the same thread as its creator.
@@ -91,9 +91,12 @@ class CONTENT_EXPORT DataFetcherSharedMemoryBase {
 
   std::unique_ptr<PollingThread> polling_thread_;
 
-  // Owning pointers. Objects in the map are deleted in dtor.
-  typedef std::map<ConsumerType, base::SharedMemory*> SharedMemoryMap;
+  typedef std::map<ConsumerType, mojo::ScopedSharedBufferHandle>
+      SharedMemoryMap;
   SharedMemoryMap shared_memory_map_;
+  typedef std::map<ConsumerType, mojo::ScopedSharedBufferMapping>

[timvolodine, 2016/06/09 17:43:47]

why do we need two maps now? is there a way to just store the
ConsumerType->Handle map?

[Sam McNally, 2016/06/10 01:07:51]

Mojo shared memory doesn't have anything that holds both a shared memory handle
and a mapping of that shared memory. The first map holds the handles to
duplicate to share with clients; the second manages lifetime of the mappings in
the browser process. There's no reason they need to be separate maps though.

[timvolodine, 2016/06/15 15:54:47]

I see, was hoping mojo would provide something equivalent to SharedMemory..

+      SharedMemoryMappingMap;
+  SharedMemoryMappingMap shared_memory_mapping_map_;
 
   DISALLOW_COPY_AND_ASSIGN(DataFetcherSharedMemoryBase);
 };