Handle recording a bitmap if copy fails.

If SkBitmapHeap::insert() returns INVALID_SLOT, assert at picture
record time so we can debug, but allow it to continue in release
mode, so that we can still capture a picture. At playback time,
print a message so we know that there was an error.

Review URL: https://codereview.appspot.com/6873050

git-svn-id: http://skia.googlecode.com/svn/trunk@6664 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkPicturePlayback.h b/src/core/SkPicturePlayback.h
index 8a7ee0a..9e495fa 100644
--- a/src/core/SkPicturePlayback.h
+++ b/src/core/SkPicturePlayback.h
@@ -93,7 +93,11 @@
     };
 
     const SkBitmap& getBitmap(SkReader32& reader) {
-        int index = reader.readInt();
+        const int index = reader.readInt();
+        if (SkBitmapHeap::INVALID_SLOT == index) {
+            SkDebugf("An invalid bitmap was recorded!\n");
+            return fBadBitmap;
+        }
         return (*fBitmaps)[index];
     }
 
@@ -190,6 +194,10 @@
     void flattenToBuffer(SkOrderedWriteBuffer&) const;
 
 private:
+    // Only used by getBitmap() if the passed in index is SkBitmapHeap::INVALID_SLOT. This empty
+    // bitmap allows playback to draw nothing and move on.
+    SkBitmap fBadBitmap;
+
     SkAutoTUnref<SkBitmapHeap> fBitmapHeap;
     SkAutoTUnref<SkPathHeap> fPathHeap;
 
diff --git a/src/core/SkPictureRecord.cpp b/src/core/SkPictureRecord.cpp
index d6f51e3..270eee5 100644
--- a/src/core/SkPictureRecord.cpp
+++ b/src/core/SkPictureRecord.cpp
@@ -657,7 +657,12 @@
 ///////////////////////////////////////////////////////////////////////////////
 
 void SkPictureRecord::addBitmap(const SkBitmap& bitmap) {
-    addInt(fBitmapHeap->insert(bitmap));
+    const int index = fBitmapHeap->insert(bitmap);
+    // In debug builds, a bad return value from insert() will crash, allowing for debugging. In
+    // release builds, the invalid value will be recorded so that the reader will know that there
+    // was a problem.
+    SkASSERT(index != SkBitmapHeap::INVALID_SLOT);
+    addInt(index);
 }
 
 void SkPictureRecord::addMatrix(const SkMatrix& matrix) {