libgui: Add dequeue/attach timeout

Adds the ability to specify the timeout when dequeueBuffer or
attachBuffer block due to the lack of a free buffer/slot. By default,
these will block indefinitely (which is signified by a timeout of -1).

When a timeout (other than -1) is specified, non-blocking mode is
disabled and the given timeout will be used instead.

Bug: 25196773
Change-Id: I17fdbeebccb7c8d878703d758ac1209608258e61
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
index f8fe8e1..64c1dd9 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.cpp
@@ -551,6 +551,11 @@
     return mSource[SOURCE_SINK]->setSingleBufferMode(singleBufferMode);
 }
 
+status_t VirtualDisplaySurface::setDequeueTimeout(nsecs_t /* timeout */) {
+    ALOGE("setDequeueTimeout not supported on VirtualDisplaySurface");
+    return INVALID_OPERATION;
+}
+
 void VirtualDisplaySurface::updateQueueBufferOutput(
         const QueueBufferOutput& qbo) {
     uint32_t w, h, transformHint, numPendingBuffers;
diff --git a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
index bde7fcf..7f451a9 100644
--- a/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
+++ b/services/surfaceflinger/DisplayHardware/VirtualDisplaySurface.h
@@ -120,7 +120,8 @@
     virtual status_t setGenerationNumber(uint32_t generationNumber);
     virtual String8 getConsumerName() const override;
     virtual uint64_t getNextFrameNumber() const override;
-    virtual status_t setSingleBufferMode(bool singleBufferMode);
+    virtual status_t setSingleBufferMode(bool singleBufferMode) override;
+    virtual status_t setDequeueTimeout(nsecs_t timeout) override;
 
     //
     // Utility methods