EDK: Convert most uses of PlatformHandleVector to std::vector<ScopedPlatformHandle>.

(And ScopedPlatformHandleVectorPtr to
std::unique_ptr<std::vector<ScopedPlatformHandle>>.)

There are a few more uses, but this change is already too big.

R=vardhan@google.com

Review URL: https://codereview.chromium.org/1478503003 .
diff --git a/mojo/edk/system/raw_channel.h b/mojo/edk/system/raw_channel.h
index beb0194..f085120 100644
--- a/mojo/edk/system/raw_channel.h
+++ b/mojo/edk/system/raw_channel.h
@@ -9,7 +9,6 @@
 #include <vector>
 
 #include "base/memory/weak_ptr.h"
-#include "mojo/edk/embedder/platform_handle_vector.h"
 #include "mojo/edk/embedder/scoped_platform_handle.h"
 #include "mojo/edk/system/message_in_transit.h"
 #include "mojo/edk/system/message_in_transit_queue.h"
@@ -67,7 +66,8 @@
     // |Shutdown()| and then (if desired) destroy it.
     virtual void OnReadMessage(
         const MessageInTransit::View& message_view,
-        embedder::ScopedPlatformHandleVectorPtr platform_handles) = 0;
+        std::unique_ptr<std::vector<embedder::ScopedPlatformHandle>>
+            platform_handles) = 0;
 
     // Called when there's a (fatal) error. This may call the |RawChannel|'s
     // |Shutdown()| and then (if desired) destroy it.
@@ -261,9 +261,10 @@
   // called when |num_platform_handles| is nonzero. Returns null if the
   // |num_platform_handles| handles are not available. Only called on the I/O
   // thread.
-  virtual embedder::ScopedPlatformHandleVectorPtr GetReadPlatformHandles(
-      size_t num_platform_handles,
-      const void* platform_handle_table) MOJO_LOCKS_EXCLUDED(write_mutex_) = 0;
+  virtual std::unique_ptr<std::vector<embedder::ScopedPlatformHandle>>
+  GetReadPlatformHandles(size_t num_platform_handles,
+                         const void* platform_handle_table)
+      MOJO_LOCKS_EXCLUDED(write_mutex_) = 0;
 
   // Writes contents in |write_buffer_no_lock()|.
   // This class guarantees that: