Prevent the usage of the texture(tile) if considered un-usable

As an example of gmail, even though clearView is called, the previous
content still show up.
This fix just use a usable flag to make sure the content
in the previously used texture is not showing up.

bug : 3215000

Change-Id: I5429a4d03547d4cd4ad10bd2153c247a4d40db7d

1 files changed, 6 insertions, 1 deletions

diff --git a/WebCore/platform/graphics/android/GLWebViewState.cpp b/WebCore/platform/graphics/android/GLWebViewState.cpp
index 9bca91a..7c2f851 100644
--- a/WebCore/platform/graphics/android/GLWebViewState.cpp
+++ b/WebCore/platform/graphics/android/GLWebViewState.cpp
@@ -97,6 +97,10 @@ GLWebViewState::~GLWebViewState()
 void GLWebViewState::setBaseLayer(BaseLayerAndroid* layer, const IntRect& rect)
 {
     android::Mutex::Autolock lock(m_baseLayerLock);
+    if (!layer) {
+        m_tiledPageA->setUsable(false);
+        m_tiledPageB->setUsable(false);
+    }
     if (m_baseLayer && layer)
         m_baseLayer->swapExtra(layer);
     m_baseLayer = layer;
@@ -233,7 +237,8 @@ void GLWebViewState::setViewport(SkRect& viewport, float scale)
             static_cast<int>(ceilf(viewport.fBottom * invTileContentHeight)));
 }
 
-bool GLWebViewState::hasContent() {
+bool GLWebViewState::hasContent()
+{
     android::Mutex::Autolock lock(m_baseLayerLock);
     return m_baseLayer;
 }