prevent that deadlock by only rpotecting shared resources

Again update may not be protected bt the mutex.

Change-Id: I8b9862c8ecafad75eea3b9e041d3063532f7bf63

chart2/source/view/charttypes/GL3DBarChart.cxx

@@ -687,11 +687,14 @@ void GL3DBarChart::moveToCorner()
 
 void GL3DBarChart::scroll(long nDelta)
 {
-    osl::MutexGuard aGuard(maMutex);
+    {
+        osl::MutexGuard aGuard(maMutex);
+
+        glm::vec3 maDir = glm::normalize(maCameraPosition - maCameraDirection);
+        maCameraPosition -= (float((nDelta/10)) * maDir);
+        mpCamera->setPosition(maCameraPosition);
+    }
 
-    glm::vec3 maDir = glm::normalize(maCameraPosition - maCameraDirection);
-    maCameraPosition -= (float((nDelta/10)) * maDir);
-    mpCamera->setPosition(maCameraPosition);
     update();
 }