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

libs/hwui/renderthread/DrawFrameTask.cpp

@@ -32,6 +32,7 @@ namespace renderthread {
 DrawFrameTask::DrawFrameTask()
         : mRenderThread(nullptr)
         , mContext(nullptr)
+        , mContentDrawBounds(0, 0, 0, 0)
         , mSyncResult(SyncResult::OK) {
 }
 
@@ -123,6 +124,7 @@ bool DrawFrameTask::syncFrameState(TreeInfo& info) {
         mLayers[i]->apply();
     }
     mLayers.clear();
+    mContext->setContentDrawBounds(mContentDrawBounds);
     mContext->prepareTree(info, mFrameInfo, mSyncQueued, mTargetNode);
 
     // This is after the prepareTree so that any pending operations