[chromium] Texture layer should not generate zero textureId quads

https://bugs.webkit.org/show_bug.cgi?id=94550

Patch by Alexandre Elias <aelias@google.com> on 2012-08-20
Reviewed by Adrienne Walker.

After a context loss, CCTextureLayerImpl would clear its textureId
but continued to produce external resources and quads with the zero
textureid.  Add early returns so that CCTextureLayerImpl becomes
inert after a context loss.

Added assertion in read lock so that dontUseOldResourcesAfterLostContext
test catches the problem.

* platform/graphics/chromium/cc/CCResourceProvider.h:
(WebCore::CCScopedLockResourceForRead::CCScopedLockResourceForRead):
* platform/graphics/chromium/cc/CCTextureLayerImpl.cpp:
(WebCore::CCTextureLayerImpl::willDraw):
(WebCore::CCTextureLayerImpl::appendQuads):
(WebCore::CCTextureLayerImpl::didDraw):
(WebCore::CCTextureLayerImpl::didLoseContext):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@126122 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/ChangeLog

@@ -1,3 +1,26 @@
+2012-08-20  Alexandre Elias  <aelias@google.com>
+
+        [chromium] Texture layer should not generate zero textureId quads
+        https://bugs.webkit.org/show_bug.cgi?id=94550
+
+        Reviewed by Adrienne Walker.
+
+        After a context loss, CCTextureLayerImpl would clear its textureId
+        but continued to produce external resources and quads with the zero
+        textureid.  Add early returns so that CCTextureLayerImpl becomes
+        inert after a context loss.
+
+        Added assertion in read lock so that dontUseOldResourcesAfterLostContext
+        test catches the problem.
+
+        * platform/graphics/chromium/cc/CCResourceProvider.h:
+        (WebCore::CCScopedLockResourceForRead::CCScopedLockResourceForRead):
+        * platform/graphics/chromium/cc/CCTextureLayerImpl.cpp:
+        (WebCore::CCTextureLayerImpl::willDraw):
+        (WebCore::CCTextureLayerImpl::appendQuads):
+        (WebCore::CCTextureLayerImpl::didDraw):
+        (WebCore::CCTextureLayerImpl::didLoseContext):
+
 2012-08-20  Kent Tamura  <tkent@chromium.org>
 
         [Chromium] Make the popup positioning code testable

Source/WebCore/platform/graphics/chromium/cc/CCResourceProvider.h

@@ -224,7 +224,10 @@ class CCScopedLockResourceForRead {
     CCScopedLockResourceForRead(CCResourceProvider* resourceProvider, CCResourceProvider::ResourceId resourceId)
         : m_resourceProvider(resourceProvider)
         , m_resourceId(resourceId)
-        , m_textureId(resourceProvider->lockForRead(resourceId)) { }
+        , m_textureId(resourceProvider->lockForRead(resourceId))
+    {
+        ASSERT(m_textureId);
+    }
 
     ~CCScopedLockResourceForRead()
     {

Source/WebCore/platform/graphics/chromium/cc/CCTextureLayerImpl.cpp

@@ -52,20 +52,24 @@ CCTextureLayerImpl::~CCTextureLayerImpl()
 
 void CCTextureLayerImpl::willDraw(CCResourceProvider* resourceProvider)
 {
+    if (!m_textureId)
+        return;
     ASSERT(!m_externalTextureResource);
     m_externalTextureResource = resourceProvider->createResourceFromExternalTexture(m_textureId);
 }
 
 void CCTextureLayerImpl::appendQuads(CCQuadSink& quadList, const CCSharedQuadState* sharedQuadState, bool&)
 {
-    ASSERT(m_externalTextureResource);
+    if (!m_externalTextureResource)
+        return;
     IntRect quadRect(IntPoint(), contentBounds());
     quadList.append(CCTextureDrawQuad::create(sharedQuadState, quadRect, m_externalTextureResource, m_premultipliedAlpha, m_uvRect, m_flipped));
 }
 
 void CCTextureLayerImpl::didDraw(CCResourceProvider* resourceProvider)
 {
-    ASSERT(m_externalTextureResource);
+    if (!m_externalTextureResource)
+        return;
     // FIXME: the following assert will not be true when sending resources to a
     // parent compositor. A synchronization scheme (double-buffering or
     // pipelining of updates) for the client will need to exist to solve this.
@@ -84,6 +88,7 @@ void CCTextureLayerImpl::dumpLayerProperties(TextStream& ts, int indent) const
 void CCTextureLayerImpl::didLoseContext()
 {
     m_textureId = 0;
+    m_externalTextureResource = 0;
 }
 
 }