Remove threading from RendererGpuVideoAcceleratorFactories

media/base/bind_to_loop.h.pump

Index: media/base/bind_to_loop.h.pump
diff --git a/media/base/bind_to_loop.h.pump b/media/base/bind_to_loop.h.pump
index 8490413eb1cc333cb2279712014f825c7487779c..b7e90714647ce8b7cc89cd489b5590c45ad07b1b 100644
--- a/media/base/bind_to_loop.h.pump
+++ b/media/base/bind_to_loop.h.pump
@@ -18,6 +18,7 @@ $var MAX_ARITY = 7
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/message_loop/message_loop_proxy.h"
+#include "base/synchronization/waitable_event.h"
 
 // This is a helper utility for base::Bind()ing callbacks on to particular
 // MessageLoops.  A typical use is when |a| (of class |A|) wants to hand a
@@ -29,9 +30,19 @@ $var MAX_ARITY = 7
 //    media::BindToLoop(MessageLoopProxy::current(),
 //                      base::Bind(&MyClass::MyMethod, this)));
 //
-// Note that like base::Bind(), BindToLoop() can't bind non-constant references,
-// and that *unlike* base::Bind(), BindToLoop() makes copies of its arguments,
-// and thus can't be used with arrays.
+// For synchronous usage, where the callback needs to be executed on another
+// MessageLoop, but the calling thread should block until the callback has been
+// completed, there is BindToLoopSync(), as below:
+//
+// Typical usage: make a request to another thread, and wait for it:
+// do_something_callback =
+//   media::BindToLoopSync(other_message_loop, &OtherClass::DoRequest, other);
+// // ...
+// do_something_callback.Run();  // will block until completion
+//
+// Note that like base::Bind(), BindToLoop() and BindToLoopSync() can't bind
+// non-constant references, and that *unlike* base::Bind(), BindToLoop*() makes
+// copies of its arguments, and thus can't be used with arrays.
 
 namespace media {
 
@@ -55,6 +66,10 @@ base::internal::PassedWrapper<ScopedVector<T> > TrampolineForward(
 
 template <typename T> struct TrampolineHelper;
 
+// Caller helper to call a base::Closure synchronously
+void TrampolineSyncCaller(const base::Closure& closure,
+                          base::WaitableEvent* waiter);
+
 $range ARITY 0..MAX_ARITY
 $for ARITY [[
 $range ARG 1..ARITY
@@ -71,6 +86,24 @@ $for ARG , [[A$(ARG) a$(ARG)]]
 $if ARITY != 0 [[, ]]
 $for ARG , [[internal::TrampolineForward(a$(ARG))]]));
   }
+  static void RunSync(
+      const scoped_refptr<base::MessageLoopProxy>& loop,
+      const base::Callback<void($for ARG , [[A$(ARG)]])>& cb
+$if ARITY != 0 [[, ]]
+$for ARG , [[A$(ARG) a$(ARG)]]
+) {
+    DCHECK(!loop->BelongsToCurrentThread());
+    base::WaitableEvent waiter(false, false);
+    loop->PostTask(
+        FROM_HERE,
+        base::Bind(
+            &TrampolineSyncCaller,
+            base::Bind(cb
+$if ARITY != 0 [[, ]]
+$for ARG , [[internal::TrampolineForward(a$(ARG))]]),
+            &waiter));
+    waiter.Wait();
+  }
 };
 
 
@@ -86,6 +119,13 @@ static base::Callback<T> BindToLoop(
 }
 
 template<typename T>
+static base::Callback<T> BindToLoopSync(
+    const scoped_refptr<base::MessageLoopProxy>& loop,
+    const base::Callback<T>& cb) {
+  return base::Bind(&internal::TrampolineHelper<T>::RunSync, loop, cb);
+}
+
+template<typename T>
 static base::Callback<T> BindToCurrentLoop(
     const base::Callback<T>& cb) {
   return BindToLoop(base::MessageLoopProxy::current(), cb);