Remove sync flush

 Bug: 13952590
 It was attempting to flush state changes after the canvas was
 destroyed, which caused layer updates to crash.

 Due to the removal of SetDisplayListData, the sync mode isn't able
 to do anything ever, so remove it.

Change-Id: I1e18ce288d81fd47cc6e612afda9476f75ecef2e
diff --git a/libs/hwui/renderthread/DrawFrameTask.cpp b/libs/hwui/renderthread/DrawFrameTask.cpp
index 372d0d0..cf6c8db 100644
--- a/libs/hwui/renderthread/DrawFrameTask.cpp
+++ b/libs/hwui/renderthread/DrawFrameTask.cpp
@@ -30,7 +30,7 @@
 namespace uirenderer {
 namespace renderthread {
 
-DrawFrameTask::DrawFrameTask() : mContext(0), mTaskMode(MODE_INVALID), mRenderNode(0) {
+DrawFrameTask::DrawFrameTask() : mContext(0), mRenderNode(0) {
 }
 
 DrawFrameTask::~DrawFrameTask() {
@@ -69,23 +69,14 @@
     LOG_ALWAYS_FATAL_IF(!mRenderNode.get(), "Cannot drawFrame with no render node!");
     LOG_ALWAYS_FATAL_IF(!mContext, "Cannot drawFrame with no CanvasContext!");
 
-    postAndWait(renderThread, MODE_FULL);
+    postAndWait(renderThread);
 
     // Reset the single-frame data
     mDirty.setEmpty();
     mRenderNode = 0;
 }
 
-void DrawFrameTask::flushStateChanges(RenderThread* renderThread) {
-    LOG_ALWAYS_FATAL_IF(!mContext, "Cannot drawFrame with no CanvasContext!");
-
-    postAndWait(renderThread, MODE_STATE_ONLY);
-}
-
-void DrawFrameTask::postAndWait(RenderThread* renderThread, TaskMode mode) {
-    LOG_ALWAYS_FATAL_IF(mode == MODE_INVALID, "That's not a real mode, silly!");
-
-    mTaskMode = mode;
+void DrawFrameTask::postAndWait(RenderThread* renderThread) {
     AutoMutex _lock(mLock);
     renderThread->queue(this);
     mSignal.wait(mLock);
@@ -97,11 +88,6 @@
     // canUnblockUiThread is temporary until WebView has a solution for syncing frame state
     bool canUnblockUiThread = syncFrameState();
 
-    if (mTaskMode == MODE_STATE_ONLY) {
-        unblockUiThread();
-        return;
-    }
-
     // Grab a copy of everything we need
     Rect dirtyCopy(mDirty);
     sp<RenderNode> renderNode = mRenderNode;
@@ -125,12 +111,9 @@
     bool hasFunctors = false;
     mContext->processLayerUpdates(&mLayers, &hasFunctors);
 
-    // If we don't have an mRenderNode this is a state flush only
-    if (mRenderNode.get()) {
-        TreeInfo info = {0};
-        mRenderNode->prepareTree(info);
-        hasFunctors |= info.hasFunctors;
-    }
+    TreeInfo info = {0};
+    mRenderNode->prepareTree(info);
+    hasFunctors |= info.hasFunctors;
 
     return !hasFunctors;
 }