cc: Disable partial updates when impl-side painting is used.

cc/layer_tree_host.cc

Index: cc/layer_tree_host.cc
diff --git a/cc/layer_tree_host.cc b/cc/layer_tree_host.cc
index 74d3cae3e4f7febc4049be9e91e0e3e34a9c6fdf..7ce7eb2c4aa6a81c4bf16ac02873f4e2c6d4ff28 100644
--- a/cc/layer_tree_host.cc
+++ b/cc/layer_tree_host.cc
@@ -157,7 +157,7 @@ void LayerTreeHost::initializeRenderer()
 
     // Update m_settings based on partial update capability.
     size_t maxPartialTextureUpdates = 0;
-    if (m_proxy->rendererCapabilities().allowPartialTextureUpdates)
+    if (m_proxy->rendererCapabilities().allowPartialTextureUpdates && !m_settings.implSidePainting)
         maxPartialTextureUpdates = std::min(m_settings.maxPartialTextureUpdates, m_proxy->maxPartialTextureUpdates());

[danakj, 2013/02/03 18:24:15]

Would it be better to have the embedder set maxPartialTextureUpdates to 0
instead, and just (D)CHECK this somewhere in our initialization code when
implSidePainting is on?

[enne (OOO), 2013/02/11 20:01:57]

I disagree; the caller is specifying a maximum, not a specific number.

In a number of cases the LTH uses less than the maximum, so adding a new case
where this happens seems quite reasonable.

     m_settings.maxPartialTextureUpdates = maxPartialTextureUpdates;