SurfaceFlinger: Implement merging of transaction objects.

Useful for WindowManager to collect multiple transactions
from independent units.

Test: Transaction_test.cpp
Change-Id: I52e89b038e3b375493169991e41cb75b67550264
diff --git a/libs/gui/LayerState.cpp b/libs/gui/LayerState.cpp
index bfc6f28..b5295f2 100644
--- a/libs/gui/LayerState.cpp
+++ b/libs/gui/LayerState.cpp
@@ -136,5 +136,101 @@
     return NO_ERROR;
 }
 
+void DisplayState::merge(const DisplayState& other) {
+    if (other.what & eSurfaceChanged) {
+        what |= eSurfaceChanged;
+        surface = other.surface;
+    }
+    if (other.what & eLayerStackChanged) {
+        what |= eLayerStackChanged;
+        layerStack = other.layerStack;
+    }
+    if (other.what & eDisplayProjectionChanged) {
+        what |= eDisplayProjectionChanged;
+        orientation = other.orientation;
+        viewport = other.viewport;
+        frame = other.frame;
+    }
+    if (other.what & eDisplaySizeChanged) {
+        what |= eDisplaySizeChanged;
+        width = other.width;
+        height = other.height;
+    }
+}
+
+void layer_state_t::merge(const layer_state_t& other) {
+    if (other.what & ePositionChanged) {
+        what |= ePositionChanged;
+        x = other.x;
+        y = other.y;
+    }
+    if (other.what & eLayerChanged) {
+        what |= eLayerChanged;
+        z = other.z;
+    }
+    if (other.what & eSizeChanged) {
+        what |= eSizeChanged;
+        w = other.w;
+        h = other.h;
+    }
+    if (other.what & eAlphaChanged) {
+        what |= eAlphaChanged;
+        alpha = other.alpha;
+    }
+    if (other.what & eMatrixChanged) {
+        what |= eMatrixChanged;
+        matrix = other.matrix;
+    }
+    if (other.what & eTransparentRegionChanged) {
+        what |= eTransparentRegionChanged;
+        transparentRegion = other.transparentRegion;
+    }
+    if (other.what & eFlagsChanged) {
+        what |= eFlagsChanged;
+        flags = other.flags;
+        mask = other.mask;
+    }
+    if (other.what & eLayerStackChanged) {
+        what |= eLayerStackChanged;
+        layerStack = other.layerStack;
+    }
+    if (other.what & eCropChanged) {
+        what |= eCropChanged;
+        crop = other.crop;
+    }
+    if (other.what & eDeferTransaction) {
+        what |= eDeferTransaction;
+        barrierHandle = other.barrierHandle;
+        barrierGbp = other.barrierGbp;
+        frameNumber = other.frameNumber;
+    }
+    if (other.what & eFinalCropChanged) {
+        what |= eFinalCropChanged;
+        finalCrop = other.finalCrop;
+    }
+    if (other.what & eOverrideScalingModeChanged) {
+        what |= eOverrideScalingModeChanged;
+        overrideScalingMode = other.overrideScalingMode;
+    }
+    if (other.what & eGeometryAppliesWithResize) {
+        what |= eGeometryAppliesWithResize;
+    }
+    if (other.what & eReparentChildren) {
+        what |= eReparentChildren;
+        reparentHandle = other.reparentHandle;
+    }
+    if (other.what & eDetachChildren) {
+        what |= eDetachChildren;
+    }
+    if (other.what & eRelativeLayerChanged) {
+        what |= eRelativeLayerChanged;
+        z = other.z;
+        relativeLayerHandle = other.relativeLayerHandle;
+    }
+    if (other.what & eReparent) {
+        what |= eReparent;
+        parentHandleForChild = other.parentHandleForChild;
+    }
+}
 
 }; // namespace android