Adds BeginFrameControl via DevTools.

content/browser/devtools/protocol/emulation_handler.h

Index: content/browser/devtools/protocol/emulation_handler.h
diff --git a/content/browser/devtools/protocol/emulation_handler.h b/content/browser/devtools/protocol/emulation_handler.h
index 8a98ce65c80e2be5374eb8cf55b843544b5b884e..5115f86848a4c5e04e677b7632d2f500729418a2 100644
--- a/content/browser/devtools/protocol/emulation_handler.h
+++ b/content/browser/devtools/protocol/emulation_handler.h
@@ -6,6 +6,8 @@
 #define CONTENT_BROWSER_DEVTOOLS_PROTOCOL_EMULATION_HANDLER_H_
 
 #include "base/macros.h"
+#include "cc/scheduler/begin_frame_source.h"
+#include "cc/surfaces/frame_sink_id.h"
 #include "content/browser/devtools/protocol/devtools_protocol_dispatcher.h"
 #include "third_party/WebKit/public/web/WebDeviceEmulationParams.h"
 
@@ -20,7 +22,9 @@ namespace page { class PageHandler; }
 
 namespace emulation {
 
-class EmulationHandler {
+class EmulatedBeginFrameSource;
+
+class EmulationHandler : public cc::ExternalBeginFrameSourceClient {
  public:
   using Response = DevToolsProtocolClient::Response;
 
@@ -28,7 +32,7 @@ class EmulationHandler {
   ~EmulationHandler();
 
   void SetRenderFrameHost(RenderFrameHostImpl* host);
-  void SetClient(std::unique_ptr<Client> client) { }
+  void SetClient(std::unique_ptr<Client> client);
   void Detached();
 
   Response SetGeolocationOverride(double* latitude,
@@ -67,7 +71,22 @@ class EmulationHandler {
   Response SetCPUThrottlingRate(double rate);
   Response SetVirtualTimePolicy(const std::string& policy, const int* budget);
 
+  Response EnableBeginFrameControl();
+  Response DisableBeginFrameControl();
+  Response SendBeginFrame(double interval,
+                          const double* frame_time,
+                          const double* deadline,
+                          std::string* out_frame_id);
+
+  void IssueBeginFrameOnSource(const cc::BeginFrameArgs& args);
+
+  // cc::ExternalBeginFrameSourceClient implementation:
+  void OnNeedsBeginFrames(bool needs_begin_frames) override;
+
  private:
+  void ClientSetNeedsBeginFrame(bool needs_begin_frame);
+  void ClientFrameCommitted(const std::string& frame_id);
+
   WebContentsImpl* GetWebContents();
   void UpdateTouchEventEmulationState();
   void UpdateDeviceEmulationState();
@@ -78,7 +97,13 @@ class EmulationHandler {
   bool device_emulation_enabled_;
   blink::WebDeviceEmulationParams device_emulation_params_;
 
+  EmulatedBeginFrameSource* begin_frame_source_;  // Not owned.
+  std::unique_ptr<cc::BeginFrameSource> original_begin_frame_source_;
+  bool needs_begin_frame_;
+
   RenderFrameHostImpl* host_;
+  std::unique_ptr<Client> client_;
+  base::WeakPtrFactory<EmulationHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(EmulationHandler);
 };