surfaceflinger: fix -Wmismatched-tags warnings

warning: struct 'HWComposer' was previously declared as a class
[-Wmismatched-tags]

warning: class 'DisplayInfo' was previously declared as a struct
[-Wmismatched-tags]

Change-Id: I13db9f8aab3a957ce8ff8d64598dae1807d6fe7e
(cherry picked from commit 646f541050)

include/gui/ISurfaceComposer.h

@@ -38,7 +38,7 @@ namespace android {
 
 class ComposerState;
 class DisplayState;
-class DisplayInfo;
+struct DisplayInfo;
 class DisplayStatInfo;
 class IDisplayEventConnection;
 class IMemoryHeap;

services/surfaceflinger/DisplayDevice.h

@@ -37,7 +37,7 @@ struct ANativeWindow;
 
 namespace android {
 
-class DisplayInfo;
+struct DisplayInfo;
 class DisplaySurface;
 class IGraphicBufferProducer;
 class Layer;

services/surfaceflinger/DisplayHardware/HWComposer.h

@@ -196,7 +196,7 @@ public:
      * This behaves more or less like a forward iterator.
      */
     class LayerListIterator {
-        friend struct HWComposer;
+        friend class HWComposer;
         HWCLayer* const mLayerList;
         size_t mIndex;