Workaround for PowerVR clear issue.

src/gpu/gl/GrGpuGL.cpp

Index: src/gpu/gl/GrGpuGL.cpp
diff --git a/src/gpu/gl/GrGpuGL.cpp b/src/gpu/gl/GrGpuGL.cpp
index 1a5048aa32d0c606adf4a31348c190f105f91924..73dd9bb15c1714e62b02d0772499fc72c6575f6c 100644
--- a/src/gpu/gl/GrGpuGL.cpp
+++ b/src/gpu/gl/GrGpuGL.cpp
@@ -1356,8 +1356,8 @@ void GrGpuGL::disableScissor() {
     }
 }
 
-void GrGpuGL::onClear(GrRenderTarget* target, const SkIRect* rect, GrColor color,
-                      bool canIgnoreRect) {
+void GrGpuGL::onGpuClear(GrRenderTarget* target, const SkIRect* rect, GrColor color,
+                         bool canIgnoreRect) {
     // parent class should never let us get here with no RT
     SkASSERT(target);
     GrGLRenderTarget* glRT = static_cast<GrGLRenderTarget*>(target);