Merge 135809 - [Chromium] Shared graphics context should only pushGroupMarker() once

Source/WebCore/platform/graphics/gpu/SharedGraphicsContext3D.cpp

Index: Source/WebCore/platform/graphics/gpu/SharedGraphicsContext3D.cpp
===================================================================
--- Source/WebCore/platform/graphics/gpu/SharedGraphicsContext3D.cpp	(revision 136022)
+++ Source/WebCore/platform/graphics/gpu/SharedGraphicsContext3D.cpp	(working copy)
@@ -42,12 +42,19 @@
         if (m_context && (!m_context->makeContextCurrent() || (m_context->getExtensions()->getGraphicsResetStatusARB() != GraphicsContext3D::NO_ERROR)))
             m_context.clear();
 
-        if (!m_context)
+        bool wasCreated = false;
+
+        if (!m_context) {
             createContext();
+            wasCreated = true;
+        }
 
         if (m_context && !m_context->makeContextCurrent())
             m_context.clear();
 
+        if (m_context && wasCreated)
+            m_context->getExtensions()->pushGroupMarkerEXT("SharedGraphicsContext");
+
         return m_context;
     }