Fix flicker from multiwindow resize

Move content bounds into DrawFrameTask. This ensures
that changes in bounds are synchronized with changes in
rendering commands, avoiding potential underdraw.

Bug: 64200212
Test: Repro steps in bug. Drag up/down on resize handle, verify
no flicker.

Change-Id: I3109acf262e23c2a7d8904f1dcbfc8273aaed65b
diff --git a/libs/hwui/renderthread/DrawFrameTask.h b/libs/hwui/renderthread/DrawFrameTask.h
index fb48062..83ecb98 100644
--- a/libs/hwui/renderthread/DrawFrameTask.h
+++ b/libs/hwui/renderthread/DrawFrameTask.h
@@ -61,6 +61,9 @@
     virtual ~DrawFrameTask();
 
     void setContext(RenderThread* thread, CanvasContext* context, RenderNode* targetNode);
+    void setContentDrawBounds(int left, int top, int right, int bottom) {
+        mContentDrawBounds.set(left, top, right, bottom);
+    }
 
     void pushLayerUpdate(DeferredLayerUpdater* layer);
     void removeLayerUpdate(DeferredLayerUpdater* layer);
@@ -82,6 +85,7 @@
     RenderThread* mRenderThread;
     CanvasContext* mContext;
     RenderNode* mTargetNode = nullptr;
+    Rect mContentDrawBounds;
 
     /*********************************************
      *  Single frame data