Make SharedGpuContext recover automatically after a context loss

third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.h

Index: third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.h
diff --git a/third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.h b/third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.h
index ec64583043b4fac3653848b9d67a6dfae9e6393f..e18973b7f965e3915af30156b14401110dfda2ec 100644
--- a/third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.h
+++ b/third_party/WebKit/Source/platform/graphics/gpu/SharedGpuContext.h
@@ -25,10 +25,12 @@ public:
     // User code can rely on this Id to determine whether long-lived
     // gpu resources are still alive in the current context.
     static unsigned contextId();
-    static gpu::gles2::GLES2Interface* gl();
-    static GrContext* gr();
-    static bool isValid();
-    static bool restore();
+    static gpu::gles2::GLES2Interface* gl(); // May re-create context if context was lost
+    static GrContext* gr(); // May re-create context if context was lost
+    static bool isValid(); // May re-create context if context was lost
+    static bool isValidWithoutRestoring();

[xidachen, 2016/09/15 18:53:35]

Is this method suppose to be called inside unit-tests only? If that's the case,
a comment describing it would be great.

[danakj, 2016/09/15 19:00:58]

(or ForTesting suffix will enforce that).

+    typedef std::function<std::unique_ptr<WebGraphicsContext3DProvider>()> ContextProviderFactory;
+    static void setContextProviderFactoryForTesting(ContextProviderFactory);
 
     enum {
         kNoSharedContext = 0,
@@ -39,8 +41,9 @@ private:
 
     SharedGpuContext();
     void createContextProviderOnMainThread(WaitableEvent*);
-    void createContextProvider();
+    void createContextProviderIfNeeded();
 
+    ContextProviderFactory m_contextProviderFactory = nullptr;
     std::unique_ptr<WebGraphicsContext3DProvider> m_contextProvider;
     unsigned m_contextId;
     friend class WTF::ThreadSpecific<SharedGpuContext>;