fix [3312683] Camera mirroring problem after switching from back to front camera

the crop as well as buffer orientation can change at every frame, when that happens
we need to reset the hwc HAL (ie: set the GEOMETRY_CHANGED flag).
currently we achieve this by taking the same code path than an actual geometry change
which is a bit more heavy than necessary.

Change-Id: I751f9ed1eeec0c27db7df2e77d5d17c6bcc17a24

services/surfaceflinger/LayerBase.cpp

@@ -503,12 +503,18 @@ void LayerBase::drawWithOpenGL(const Region& clip, const Texture& texture) const
 
 void LayerBase::setBufferCrop(const Rect& crop) {
     if (!crop.isEmpty()) {
-        mBufferCrop = crop;
+        if (mBufferCrop != crop) {
+            mBufferCrop = crop;
+            mFlinger->invalidateHwcGeometry();
+        }
     }
 }
 
 void LayerBase::setBufferTransform(uint32_t transform) {
-    mBufferTransform = transform;
+    if (mBufferTransform != transform) {
+        mBufferTransform = transform;
+        mFlinger->invalidateHwcGeometry();
+    }
 }
 
 void LayerBase::dump(String8& result, char* buffer, size_t SIZE) const

services/surfaceflinger/SurfaceFlinger.cpp

@@ -460,7 +460,7 @@ void SurfaceFlinger::handleTransaction(uint32_t transactionFlags)
         handleTransactionLocked(transactionFlags, ditchedLayers);
         mLastTransactionTime = systemTime() - now;
         mDebugInTransaction = 0;
-        mHwWorkListDirty = true;
+        invalidateHwcGeometry();
         // here the transaction has been committed
     }
 
@@ -726,13 +726,18 @@ void SurfaceFlinger::handlePageFlip()
 
             mWormholeRegion = screenRegion.subtract(opaqueRegion);
             mVisibleRegionsDirty = false;
-            mHwWorkListDirty = true;
+            invalidateHwcGeometry();
         }
 
     unlockPageFlip(currentLayers);
     mDirtyRegion.andSelf(screenRegion);
 }
 
+void SurfaceFlinger::invalidateHwcGeometry()
+{
+    mHwWorkListDirty = true;
+}
+
 bool SurfaceFlinger::lockPageFlip(const LayerVector& currentLayers)
 {
     bool recomputeVisibleRegions = false;
@@ -1586,7 +1591,7 @@ status_t SurfaceFlinger::onTransact(
             case 1008:  // toggle use of hw composer
                 n = data.readInt32();
                 mDebugDisableHWC = n ? 1 : 0;
-                mHwWorkListDirty = true;
+                invalidateHwcGeometry();
                 // fall-through...
             case 1004:{ // repaint everything
                 Mutex::Autolock _l(mStateLock);

services/surfaceflinger/SurfaceFlinger.h

@@ -208,6 +208,7 @@ public:
     status_t removeLayer(const sp<LayerBase>& layer);
     status_t addLayer(const sp<LayerBase>& layer);
     status_t invalidateLayerVisibility(const sp<LayerBase>& layer);
+    void invalidateHwcGeometry();
 
     sp<Layer> getLayer(const sp<ISurface>& sur) const;