Remove ContextProvider::IsContextLost.

cc/test/test_gles2_interface.cc

Index: cc/test/test_gles2_interface.cc
diff --git a/cc/test/test_gles2_interface.cc b/cc/test/test_gles2_interface.cc
index 6ce087fe222e7579787a4ef373e4d63bd4164700..38b1d2014797665dea5105a779a359d3f859a036 100644
--- a/cc/test/test_gles2_interface.cc
+++ b/cc/test/test_gles2_interface.cc
@@ -6,6 +6,7 @@
 
 #include "base/logging.h"
 #include "cc/test/test_web_graphics_context_3d.h"
+#include "gpu/GLES2/gl2extchromium.h"
 
 namespace cc {
 
@@ -423,4 +424,10 @@ void TestGLES2Interface::LoseContextCHROMIUM(GLenum current, GLenum other) {
   test_context_->loseContextCHROMIUM(current, other);
 }
 
+GLenum TestGLES2Interface::GetGraphicsResetStatusKHR() {
+  if (test_context_->isContextLost())
+    return GL_UNKNOWN_CONTEXT_RESET_KHR;
+  return GL_NO_ERROR;
+}
+
 }  // namespace cc