Handle offscreen animations correctly

A bug in software rendering caused animations on views that are offscreen
to not get drawn, therefore the animation doesn't continue (since old-style
animations depend on the logic in the drawing code to keep running). Fix is
to special case the isAnimating case in ViewRoot to go ahead and schedule
a traversal even if the dirty rect does not intersect with the visible region.

Issue #7396035 Animations starting offscreen don't draw run/end/draw properly (sw rendering only)

Change-Id: Iae25b3a424ddc5a16ba431ecd68cf42d5500db3f

core/java/android/view/ViewRootImpl.java

@@ -861,7 +861,7 @@ public final class ViewRootImpl implements ViewParent,
         if (dirty == null) {
             invalidate();
             return null;
-        } else if (dirty.isEmpty()) {
+        } else if (dirty.isEmpty() && !mIsAnimating) {
             return null;
         }
 
@@ -890,14 +890,14 @@ public final class ViewRootImpl implements ViewParent,
         // Intersect with the bounds of the window to skip
         // updates that lie outside of the visible region
         final float appScale = mAttachInfo.mApplicationScale;
-        if (localDirty.intersect(0, 0,
-                (int) (mWidth * appScale + 0.5f), (int) (mHeight * appScale + 0.5f))) {
-            if (!mWillDrawSoon) {
-                scheduleTraversals();
-            }
-        } else {
+        final boolean intersected = localDirty.intersect(0, 0,
+                (int) (mWidth * appScale + 0.5f), (int) (mHeight * appScale + 0.5f));
+        if (!intersected) {
             localDirty.setEmpty();
         }
+        if (!mWillDrawSoon && (intersected || mIsAnimating)) {
+            scheduleTraversals();
+        }
 
         return null;
     }

libs/hwui/DisplayListRenderer.cpp

@@ -763,16 +763,17 @@ void DisplayList::outputViewProperties(OpenGLRenderer& renderer, char* indent) {
         }
     }
     if (mAlpha < 1 && !mCaching) {
-        // TODO: should be able to store the size of a DL at record time and not
-        // have to pass it into this call. In fact, this information might be in the
-        // location/size info that we store with the new native transform data.
-        int flags = SkCanvas::kHasAlphaLayer_SaveFlag;
-        if (mClipChildren) {
-            flags |= SkCanvas::kClipToLayer_SaveFlag;
+        if (!mHasOverlappingRendering) {
+            ALOGD("%s%s %.2f", indent, "SetAlpha", mAlpha);
+        } else {
+            int flags = SkCanvas::kHasAlphaLayer_SaveFlag;
+            if (mClipChildren) {
+                flags |= SkCanvas::kClipToLayer_SaveFlag;
+            }
+            ALOGD("%s%s %.2f, %.2f, %.2f, %.2f, %d, 0x%x", indent, "SaveLayerAlpha",
+                    (float) 0, (float) 0, (float) mRight - mLeft, (float) mBottom - mTop,
+                    mMultipliedAlpha, flags);
         }
-        ALOGD("%s%s %.2f, %.2f, %.2f, %.2f, %d, 0x%x", indent, "SaveLayerAlpha",
-                (float) 0, (float) 0, (float) mRight - mLeft, (float) mBottom - mTop,
-                mMultipliedAlpha, flags);
     }
     if (mClipChildren) {
         ALOGD("%s%s %.2f, %.2f, %.2f, %.2f", indent, "ClipRect", 0.0f, 0.0f,