Add can-ignore-rect hint to clear call

src/gpu/GrGpu.cpp

Index: src/gpu/GrGpu.cpp
===================================================================
--- src/gpu/GrGpu.cpp	(revision 12054)
+++ src/gpu/GrGpu.cpp	(working copy)
@@ -205,6 +205,7 @@
 
 void GrGpu::clear(const SkIRect* rect,
                   GrColor color,
+                  bool canIgnoreRect,
                   GrRenderTarget* renderTarget) {
     GrDrawState::AutoRenderTargetRestore art;
     if (NULL != renderTarget) {
@@ -215,7 +216,7 @@
         return;
     }
     this->handleDirtyContext();
-    this->onClear(rect, color);
+    this->onClear(rect, color, canIgnoreRect);
 }
 
 void GrGpu::forceRenderTargetFlush() {