cc: Give ownership of render passes to the renderer when drawing a frame.

cc/direct_renderer.cc

Index: cc/direct_renderer.cc
diff --git a/cc/direct_renderer.cc b/cc/direct_renderer.cc
index 7fbd16c58778fb269605d11b0cdac5a0cd13cbb2..eebb44ad2d72181b1c9f63364e6ed128e63ffac6 100644
--- a/cc/direct_renderer.cc
+++ b/cc/direct_renderer.cc
@@ -149,7 +149,7 @@ void DirectRenderer::decideRenderPassAllocationsForFrame(const RenderPassList& r
     }
 }
 
-void DirectRenderer::drawFrame(const RenderPassList& renderPassesInDrawOrder, const RenderPassIdHashMap& renderPassesById)
+void DirectRenderer::drawFrame(RenderPassList& renderPassesInDrawOrder, RenderPassIdHashMap& renderPassesById)
 {
     TRACE_EVENT0("cc", "DirectRenderer::drawFrame");
     const RenderPass* rootRenderPass = renderPassesInDrawOrder.back();
@@ -165,6 +165,9 @@ void DirectRenderer::drawFrame(const RenderPassList& renderPassesInDrawOrder, co
     for (size_t i = 0; i < renderPassesInDrawOrder.size(); ++i)
         drawRenderPass(frame, renderPassesInDrawOrder[i]);
     finishDrawingFrame(frame);
+
+    renderPassesInDrawOrder.clear();
+    renderPassesById.clear();
 }
 
 gfx::RectF DirectRenderer::computeScissorRectForRenderPass(const DrawingFrame& frame)