Merge \"Redraw if dirty during stopped when resumed\" into nyc-dev

am: 5b4ff21a74

Change-Id: If4eedb4a4c1ff6d4e96f8b0db4ddd846a2967a9f

libs/hwui/renderthread/CanvasContext.cpp

@@ -149,6 +149,8 @@ void CanvasContext::setStopped(bool stopped) {
             if (mEglManager.isCurrent(mEglSurface)) {
                 mEglManager.makeCurrent(EGL_NO_SURFACE);
             }
+        } else if (mIsDirty && hasSurface()) {
+            mRenderThread.postFrameCallback(this);
         }
     }
 }
@@ -231,6 +233,8 @@ void CanvasContext::prepareTree(TreeInfo& info, int64_t* uiFrameInfo,
     freePrefetchedLayers(info.observer);
     GL_CHECKPOINT(MODERATE);
 
+    mIsDirty = true;
+
     if (CC_UNLIKELY(!mNativeSurface.get())) {
         mCurrentFrameInfo->addFlag(FrameInfoFlags::SkippedFrame);
         info.out.canDrawThisFrame = false;
@@ -504,6 +508,7 @@ void CanvasContext::draw() {
     // Even if we decided to cancel the frame, from the perspective of jank
     // metrics the frame was swapped at this point
     mCurrentFrameInfo->markSwapBuffers();
+    mIsDirty = false;
 
     if (drew || mEglManager.damageRequiresSwap()) {
         if (CC_UNLIKELY(!mEglManager.swapBuffers(frame, screenDirty))) {

libs/hwui/renderthread/CanvasContext.h

@@ -187,7 +187,12 @@ private:
     EglManager& mEglManager;
     sp<Surface> mNativeSurface;
     EGLSurface mEglSurface = EGL_NO_SURFACE;
+    // stopped indicates the CanvasContext will reject actual redraw operations,
+    // and defer repaint until it is un-stopped
     bool mStopped = false;
+    // CanvasContext is dirty if it has received an update that it has not
+    // painted onto its surface.
+    bool mIsDirty = false;
     bool mBufferPreserved = false;
     SwapBehavior mSwapBehavior = kSwap_default;
     struct SwapHistory {