Simplify TaskManager fallback path

Change-Id: Ie3833449f7fe6aa69b9f71eb8bab1bef0fe434aa

libs/hwui/PathCache.cpp

@@ -446,9 +446,7 @@ void PathCache::precache(const SkPath* path, const SkPaint* paint) {
         if (mProcessor == nullptr) {
             mProcessor = new PathProcessor(Caches::getInstance());
         }
-        if (!mProcessor->add(task)) {
-            mProcessor->process(task);
-        }
+        mProcessor->add(task);
     }
 }
 

libs/hwui/TessellationCache.cpp

@@ -386,10 +386,7 @@ void TessellationCache::precacheShadows(const Matrix4* drawTransform, const Rect
     if (mShadowProcessor == nullptr) {
         mShadowProcessor = new ShadowProcessor(Caches::getInstance());
     }
-    if (!mShadowProcessor->add(task)) {
-        mShadowProcessor->process(task);
-    }
-
+    mShadowProcessor->add(task);
     task->incStrong(nullptr); // not using sp<>s, so manually ref while in the cache
     mShadowCache.put(key, task.get());
 }
@@ -424,9 +421,7 @@ TessellationCache::Buffer* TessellationCache::getOrCreateBuffer(
         if (mProcessor == nullptr) {
             mProcessor = new TessellationProcessor(Caches::getInstance());
         }
-        if (!mProcessor->add(task)) {
-            mProcessor->process(task);
-        }
+        mProcessor->add(task);
         mCache.put(entry, buffer);
     }
     return buffer;

libs/hwui/thread/TaskProcessor.h

@@ -39,7 +39,17 @@ public:
     TaskProcessor(TaskManager* manager): mManager(manager) { }
     virtual ~TaskProcessor() { }
 
-    bool add(const sp<Task<T> >& task);
+    void add(const sp<Task<T> >& task) {
+        if (!addImpl(task)) {
+            // fall back to immediate execution
+            process(task);
+        }
+    }
+
+    virtual void onProcess(const sp<Task<T> >& task) = 0;
+
+private:
+    bool addImpl(const sp<Task<T> >& task);
 
     virtual void process(const sp<TaskBase>& task) override {
         sp<Task<T> > realTask = static_cast<Task<T>* >(task.get());
@@ -48,13 +58,11 @@ public:
         onProcess(realTask);
     }
 
-    virtual void onProcess(const sp<Task<T> >& task) = 0;
-
     TaskManager* mManager;
 };
 
 template<typename T>
-bool TaskProcessor<T>::add(const sp<Task<T> >& task) {
+bool TaskProcessor<T>::addImpl(const sp<Task<T> >& task) {
     if (mManager) {
         sp<TaskProcessor<T> > self(this);
         return mManager->addTask(task, self);