Add ContextProvider::InvalidateGrContext to reset GL state in GrContext

cc/output/context_provider.h

Index: cc/output/context_provider.h
diff --git a/cc/output/context_provider.h b/cc/output/context_provider.h
index 71d06bd7591d22f180f7a395b5be412d733b03bb..7acadb84913b4fa99af187c1150f97f795e5f4ed 100644
--- a/cc/output/context_provider.h
+++ b/cc/output/context_provider.h
@@ -9,8 +9,7 @@
 #include "base/memory/ref_counted.h"
 #include "cc/base/cc_export.h"
 #include "gpu/command_buffer/common/capabilities.h"
-
-class GrContext;
+#include "third_party/skia/include/gpu/GrContext.h"
 
 namespace base {
 class Lock;
@@ -44,6 +43,9 @@ class ContextProvider : public base::RefCountedThreadSafe<ContextProvider> {
     CC_EXPORT Capabilities();
   };
 
+  // invalidate the cached OGL state in GrContext

[piman, 2015/05/06 22:03:40]

nit: "Invalidates" (uppercase, descriptive rather than imperative), and end with
a period.

[CodeByThePound, 2015/05/06 22:27:55]

Acknowledged.

+  void InvalidateGrContext(uint32_t state = kAll_GrBackendState);

[piman, 2015/05/06 22:03:40]

nit: no default arguments, per style guide

[CodeByThePound, 2015/05/06 22:27:55]

Acknowledged.

+
   // Sets up a lock so this context can be used from multiple threads.
   virtual void SetupLock() = 0;
 
@@ -87,6 +89,9 @@ class ContextProvider : public base::RefCountedThreadSafe<ContextProvider> {
  protected:
   friend class base::RefCountedThreadSafe<ContextProvider>;
   virtual ~ContextProvider() {}
+
+ private:
+  virtual void DoInvalidateGrContext(uint32_t) = 0;
 };
 
 }  // namespace cc