Workaround double blit failure

An issue occurs on Stingray where calling glTexSubImage2d in order to blit an
update to a texture fails silently if the texture has already been updated this
frame.

With this change, we now draw the tile off-screen to work around the issue just
before the second blit is required. This way, the second blit succeeds.

bug:6630040

Change-Id: I07213954669b0f3d3f5b87a748a591e532b097b4

1 files changed, 2 insertions, 0 deletions

diff --git a/Source/WebCore/platform/graphics/android/rendering/Tile.h b/Source/WebCore/platform/graphics/android/rendering/Tile.h
index 2dc5414..b045f1f 100644
--- a/Source/WebCore/platform/graphics/android/rendering/Tile.h
+++ b/Source/WebCore/platform/graphics/android/rendering/Tile.h
@@ -127,6 +127,7 @@ public:
     int y() const { return m_y; }
     TileTexture* frontTexture() { return m_frontTexture; }
     TileTexture* backTexture() { return m_backTexture; }
+    TileTexture* lastDrawnTexture() { return m_lastDrawnTexture; }
 
     // only used for prioritization - the higher, the more relevant the tile is
     unsigned long long drawCount() { return m_drawCount; }
@@ -151,6 +152,7 @@ private:
 
     TileTexture* m_frontTexture;
     TileTexture* m_backTexture;
+    TileTexture* m_lastDrawnTexture;
     float m_scale;
 
     // used to signal that the that the tile is out-of-date and needs to be