attempt to fix bug 5313580

the working theory here is that a Surface object has become non-promotable
because it lost its last reference; later Surface::readFromParcel is called
the previous surface is found in the cache, but can't be promoted. this causes
a new Surface object to be created which will promptly try to connect to the
CPU_API -- this in turn will fail because the previous (now dead) surface is
still connected.

To fix this, we make sure to disconnect from the SurfaceTexture when
Surface[TextureClient] is destroyed.

Change-Id: I422234868a05d7b7d283e9d5a85f7ab79e65d8a9

include/gui/SurfaceTextureClient.h

@@ -40,6 +40,7 @@ public:
 
 protected:
     SurfaceTextureClient();
+    virtual ~SurfaceTextureClient();
     void setISurfaceTexture(const sp<ISurfaceTexture>& surfaceTexture);
 
 private:

libs/gui/SurfaceTextureClient.cpp

@@ -36,6 +36,12 @@ SurfaceTextureClient::SurfaceTextureClient() {
     SurfaceTextureClient::init();
 }
 
+SurfaceTextureClient::~SurfaceTextureClient() {
+    if (mConnectedToCpu) {
+        SurfaceTextureClient::disconnect(NATIVE_WINDOW_API_CPU);
+    }
+}
+
 void SurfaceTextureClient::init() {
     // Initialize the ANativeWindow function pointers.
     ANativeWindow::setSwapInterval  = hook_setSwapInterval;