Handle a case that View's size becomes empty unexpectedly

BUG=458280

Review URL: https://codereview.chromium.org/926573002

Cr-Commit-Position: refs/heads/master@{#317889}

Review URL: https://codereview.chromium.org/989363002

Cr-Commit-Position: refs/branch-heads/2311@{#190}
Cr-Branched-From: 09b7de5-refs/heads/master@{#317474}

ui/android/java/src/org/chromium/ui/resources/dynamics/ViewResourceAdapter.java

@@ -6,6 +6,7 @@
 
 import android.graphics.Bitmap;
 import android.graphics.Canvas;
+import android.graphics.Color;
 import android.graphics.Rect;
 import android.view.View;
 import android.view.View.OnLayoutChangeListener;
@@ -47,16 +48,19 @@ public ViewResourceAdapter(View view) {
     public Bitmap getBitmap() {
         if (!isDirty()) return mBitmap;
         TraceEvent.begin("ViewResourceAdapter:getBitmap");
-        validateBitmap();
+        if (validateBitmap()) {
+            Canvas canvas = new Canvas(mBitmap);
 
-        Canvas canvas = new Canvas(mBitmap);
+            onCaptureStart(canvas, mDirtyRect.isEmpty() ? null : mDirtyRect);
 
-        onCaptureStart(canvas, mDirtyRect.isEmpty() ? null : mDirtyRect);
+            if (!mDirtyRect.isEmpty()) canvas.clipRect(mDirtyRect);
+            mView.draw(canvas);
 
-        if (!mDirtyRect.isEmpty()) canvas.clipRect(mDirtyRect);
-        mView.draw(canvas);
-
-        onCaptureEnd();
+            onCaptureEnd();
+        } else {
+            assert mBitmap.getWidth() == 1 && mBitmap.getHeight() == 1;
+            mBitmap.setPixel(0, 0, Color.TRANSPARENT);
+        }
 
         mDirtyRect.setEmpty();
         TraceEvent.end("ViewResourceAdapter:getBitmap");
@@ -143,22 +147,30 @@ protected void computeContentAperture(Rect outContentAperture) {
         outContentAperture.set(0, 0, mView.getWidth(), mView.getHeight());
     }
 
-    private void validateBitmap() {
+    /**
+     * @return Whether |mBitmap| is corresponding to |mView| or not.
+     */
+    private boolean validateBitmap() {
+        int viewWidth = mView.getWidth();
+        int viewHeight = mView.getHeight();
+        boolean isEmpty = viewWidth == 0 || viewHeight == 0;
+        if (isEmpty) {
+            viewWidth = 1;
+            viewHeight = 1;
+        }
         if (mBitmap != null
-                && (mBitmap.getWidth() != mView.getWidth()
-                || mBitmap.getHeight() != mView.getHeight())) {
+                && (mBitmap.getWidth() != viewWidth || mBitmap.getHeight() != viewHeight)) {
             mBitmap.recycle();
             mBitmap = null;
         }
 
-        if (mView.getWidth() == 0 || mView.getHeight() == 0) return;
-
         if (mBitmap == null) {
-            mBitmap = Bitmap.createBitmap(
-                    mView.getWidth(), mView.getHeight(), Bitmap.Config.ARGB_8888);
+            mBitmap = Bitmap.createBitmap(viewWidth, viewHeight, Bitmap.Config.ARGB_8888);
             mBitmap.setHasAlpha(true);
-            mDirtyRect.set(0, 0, mView.getWidth(), mView.getHeight());
+            mDirtyRect.set(0, 0, viewWidth, viewHeight);
             mBitmapSize.set(0, 0, mBitmap.getWidth(), mBitmap.getHeight());
         }
+
+        return !isEmpty;
     }
-}
+}