BufferQueue improvements and APIs changes

this is the first step of a series of improvements to
BufferQueue. A few things happen in this change:

- setSynchronousMode() goes away as well as the SynchronousModeAllowed flag
- BufferQueue now defaults to (what used to be) synchronous mode
- a new "controlled by app" flag is passed when creating consumers and producers
  those flags are used to put the BufferQueue in a mode where it
  will never block if both flags are set. This is achieved by:
  - returning an error from dequeueBuffer() if it would block
  - making sure a buffer is always available by replacing
    the previous buffer with the new one in queueBuffer()
    (note: this is similar to what asynchrnous mode used to be)

Note: in this change EGL's swap-interval 0 is broken; this will be
fixed in another change.

Change-Id: I691f9507d6e2e158287e3039f2a79a4d4434211d
diff --git a/services/surfaceflinger/SurfaceTextureLayer.cpp b/services/surfaceflinger/SurfaceTextureLayer.cpp
index d0f0dae..b76dc0c 100644
--- a/services/surfaceflinger/SurfaceTextureLayer.cpp
+++ b/services/surfaceflinger/SurfaceTextureLayer.cpp
@@ -28,7 +28,7 @@
 
 
 SurfaceTextureLayer::SurfaceTextureLayer(const sp<SurfaceFlinger>& flinger)
-    : BufferQueue(true), flinger(flinger) {
+    : BufferQueue(), flinger(flinger) {
 }
 
 SurfaceTextureLayer::~SurfaceTextureLayer() {
@@ -51,32 +51,5 @@
     flinger->postMessageAsync( new MessageCleanUpList(flinger, this) );
 }
 
-status_t SurfaceTextureLayer::connect(int api, QueueBufferOutput* output) {
-    status_t err = BufferQueue::connect(api, output);
-    if (err == NO_ERROR) {
-        switch(api) {
-            case NATIVE_WINDOW_API_MEDIA:
-            case NATIVE_WINDOW_API_CAMERA:
-                // Camera preview and videos are rate-limited on the producer
-                // side.  If enabled for this build, we use async mode to always
-                // show the most recent frame at the cost of requiring an
-                // additional buffer.
-#ifndef NEVER_DEFAULT_TO_ASYNC_MODE
-                err = setSynchronousMode(false);
-                break;
-#endif
-                // fall through to set synchronous mode when not defaulting to
-                // async mode.
-            default:
-                err = setSynchronousMode(true);
-                break;
-        }
-        if (err != NO_ERROR) {
-            disconnect(api);
-        }
-    }
-    return err;
-}
-
 // ---------------------------------------------------------------------------
 }; // namespace android