[Paint Preview] More eagerly release native memory on exit

To ensure we are cleaning up native memory promptly this CL invokes
recycle on all bitmaps prior to ceasing to use them.

Change-Id: If76397cdd8f232eff9992763d2b1cf07ecaed07c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2471598Reviewed-by: Mehran Mahmoudi <mahmoudi@chromium.org>
Commit-Queue: Calder Kitagawa <ckitagawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#817152}

components/paint_preview/player/android/java/src/org/chromium/components/paintpreview/player/PlayerManager.java

@@ -231,6 +231,10 @@ public class PlayerManager {
             mDelegate.destroy();
             mDelegate = null;
         }
+        if (mRootFrameCoordinator != null) {
+            mRootFrameCoordinator.destroy();
+            mRootFrameCoordinator = null;
+        }
     }
 
     public View getView() {

components/paint_preview/player/android/java/src/org/chromium/components/paintpreview/player/frame/PlayerFrameBitmapState.java

@@ -97,10 +97,17 @@ public class PlayerFrameBitmapState {
     /**
      * Clears state so in-flight requests abort upon return.
      */
-    void clear() {
-        mBitmapMatrix = null;
+    void destroy() {
         mRequiredBitmaps = null;
         mPendingBitmapRequests = null;
+        for (int i = 0; i < mBitmapMatrix.length; i++) {
+            for (int j = 0; j < mBitmapMatrix[i].length; j++) {
+                if (mBitmapMatrix[i][j] != null) {
+                    mBitmapMatrix[i][j].destroy();
+                }
+            }
+        }
+        mBitmapMatrix = null;
     }
 
     /**
@@ -117,19 +124,6 @@ public class PlayerFrameBitmapState {
         mInitialMissingVisibleBitmaps = null;
     }
 
-    /**
-     * Clears all the required bitmaps before they are re-set in {@link #requestBitmapForRect()}
-     */
-    void clearRequiredBitmaps() {
-        if (mRequiredBitmaps == null) return;
-
-        for (int row = 0; row < mRequiredBitmaps.length; row++) {
-            for (int col = 0; col < mRequiredBitmaps[row].length; col++) {
-                mRequiredBitmaps[row][col] = false;
-            }
-        }
-    }
-
     /**
      * Requests bitmaps for tiles that overlap with the provided rect. Also requests bitmaps for
      * adjacent tiles.
@@ -137,7 +131,7 @@ public class PlayerFrameBitmapState {
      */
     void requestBitmapForRect(Rect viewportRect) {
         if (mRequiredBitmaps == null || mBitmapMatrix == null) return;
-        clearVisibleBitmaps();
+        clearBeforeRequest();
 
         final int rowStart =
                 Math.max(0, (int) Math.floor((double) viewportRect.top / mTileSize.getHeight()));
@@ -248,12 +242,18 @@ public class PlayerFrameBitmapState {
         mStateController.stateUpdated(this);
     }
 
-    private void clearVisibleBitmaps() {
-        if (mVisibleBitmaps == null) return;
+    private void clearBeforeRequest() {
+        if (mVisibleBitmaps == null || mRequiredBitmaps == null) return;
+
+        assert mVisibleBitmaps.length == mRequiredBitmaps.length;
+        assert (mVisibleBitmaps.length > 0)
+                ? mVisibleBitmaps[0].length == mRequiredBitmaps[0].length
+                : true;
 
         for (int row = 0; row < mVisibleBitmaps.length; row++) {
             for (int col = 0; col < mVisibleBitmaps[row].length; col++) {
                 mVisibleBitmaps[row][col] = false;
+                mRequiredBitmaps[row][col] = false;
             }
         }
     }

components/paint_preview/player/android/java/src/org/chromium/components/paintpreview/player/frame/PlayerFrameBitmapStateController.java

@@ -37,6 +37,17 @@ public class PlayerFrameBitmapStateController {
         mTaskRunner = taskRunner;
     }
 
+    void destroy() {
+        if (mLoadingBitmapState != null) {
+            mLoadingBitmapState.destroy();
+            mLoadingBitmapState = null;
+        }
+        if (mVisibleBitmapState != null) {
+            mVisibleBitmapState.destroy();
+            mVisibleBitmapState = null;
+        }
+    }
+
     @VisibleForTesting
     void swapForTest() {
         swap(mLoadingBitmapState);
@@ -76,7 +87,7 @@ public class PlayerFrameBitmapStateController {
         assert mLoadingBitmapState == newState;
         // Clear the state to stop potential stragling updates.
         if (mVisibleBitmapState != null) {
-            mVisibleBitmapState.clear();
+            mVisibleBitmapState.destroy();
         }
         mVisibleBitmapState = newState;
         mLoadingBitmapState = null;
@@ -119,7 +130,7 @@ public class PlayerFrameBitmapStateController {
         // Invalidate an in-progress load if there is one. We only want one new scale factor fetched
         // at a time. NOTE: we clear then null as the bitmap callbacks still hold a reference to the
         // state so it won't be GC'd right away.
-        mLoadingBitmapState.clear();
+        mLoadingBitmapState.destroy();
         mLoadingBitmapState = null;
     }
 }

components/paint_preview/player/android/java/src/org/chromium/components/paintpreview/player/frame/PlayerFrameCoordinator.java

@@ -69,6 +69,13 @@ public class PlayerFrameCoordinator {
         PropertyModelChangeProcessor.create(model, mView, PlayerFrameViewBinder::bind);
     }
 
+    public void destroy() {
+        mMediator.destroy();
+        for (PlayerFrameCoordinator subframe : mSubFrames) {
+            subframe.destroy();
+        }
+    }
+
     public void setAcceptUserInput(boolean acceptUserInput) {
         if (mScrollController != null) mScrollController.setAcceptUserInput(acceptUserInput);
         if (mScaleController != null) mScaleController.setAcceptUserInput(acceptUserInput);

components/paint_preview/player/android/java/src/org/chromium/components/paintpreview/player/frame/PlayerFrameMediator.java

@@ -95,6 +95,10 @@ class PlayerFrameMediator implements PlayerFrameViewDelegate, PlayerFrameMediato
         mViewport.setScale(0f);
     }
 
+    void destroy() {
+        mBitmapStateController.destroy();
+    }
+
     @VisibleForTesting
     PlayerFrameBitmapStateController getBitmapStateControllerForTest() {
         return mBitmapStateController;
@@ -251,9 +255,6 @@ class PlayerFrameMediator implements PlayerFrameViewDelegate, PlayerFrameMediato
             mModel.set(PlayerFrameProperties.VIEWPORT, viewportRect);
         }
 
-        // Clear the required bitmaps matrix. It will be updated in #requestBitmapForTile.
-        activeLoadingState.clearRequiredBitmaps();
-
         // Request bitmaps for tiles inside the view port that don't already have a bitmap.
         activeLoadingState.requestBitmapForRect(viewportRect);
     }