Add method to explicitly create Surface.

It is sometimes necessary for a SurfaceControl client to request the
associated Surface object be created rather than reuse the cached
value. This changelist adds an additional method that performs the
same creation operations as if the Surface object was created for the
first time.

Bug: 62108743
Test: go/wm-smoke
Change-Id: I2f460f20b2d16ed9ff81cb36842bcd2f8641e03c
diff --git a/libs/gui/SurfaceControl.cpp b/libs/gui/SurfaceControl.cpp
index bf8a815..58bd273 100644
--- a/libs/gui/SurfaceControl.cpp
+++ b/libs/gui/SurfaceControl.cpp
@@ -237,17 +237,30 @@
     return parcel->writeStrongBinder(IInterface::asBinder(bp));
 }
 
+sp<Surface> SurfaceControl::generateSurfaceLocked() const
+{
+    // This surface is always consumed by SurfaceFlinger, so the
+    // producerControlledByApp value doesn't matter; using false.
+    mSurfaceData = new Surface(mGraphicBufferProducer, false);
+
+    return mSurfaceData;
+}
+
 sp<Surface> SurfaceControl::getSurface() const
 {
     Mutex::Autolock _l(mLock);
     if (mSurfaceData == 0) {
-        // This surface is always consumed by SurfaceFlinger, so the
-        // producerControlledByApp value doesn't matter; using false.
-        mSurfaceData = new Surface(mGraphicBufferProducer, false);
+        return generateSurfaceLocked();
     }
     return mSurfaceData;
 }
 
+sp<Surface> SurfaceControl::createSurface() const
+{
+    Mutex::Autolock _l(mLock);
+    return generateSurfaceLocked();
+}
+
 sp<IBinder> SurfaceControl::getHandle() const
 {
     Mutex::Autolock lock(mLock);