Revert of [DevTools] Throttle device emulation with respect to produced frames. (patchset #1 id:1 of https://codereview.chromium.org/1436983003/ )

Reason for revert:
Broke some tests.

Original issue's description:
> [DevTools] Throttle device emulation with respect to produced frames.
>
> We do not issue new device emulation command until the frame arrives (guarded by timeout).
>
> BUG=none

TBR=pfeldman@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=none

Review URL: https://codereview.chromium.org/1436823004

Cr-Commit-Position: refs/heads/master@{#359335}

3 files changed, 6 insertions, 45 deletions

diff --git a/content/browser/devtools/protocol/emulation_handler.cc b/content/browser/devtools/protocol/emulation_handler.cc
index 9659991..cae9f00 100644
--- a/content/browser/devtools/protocol/emulation_handler.cc
+++ b/content/browser/devtools/protocol/emulation_handler.cc
@@ -35,19 +35,11 @@ ui::GestureProviderConfigType TouchEmulationConfigurationToType(
   return result;
 }
 
-// When continuously applying device emulation, we wait for compositor frame
-// before applying new values. If the frame does not arrive during this
-// timeout, we proceed anyway.
-const int kFrameTimeoutMs = 67;
-
 }  // namespace
 
 EmulationHandler::EmulationHandler(page::PageHandler* page_handler)
     : touch_emulation_enabled_(false),
       device_emulation_enabled_(false),
-      device_emulation_needs_update_(false),
-      device_emulation_waiting_for_frame_(false),
-      frame_timer_(new base::Timer(false, false)),
       page_handler_(page_handler),
       host_(nullptr)
 {
@@ -67,14 +59,14 @@ void EmulationHandler::SetRenderFrameHost(RenderFrameHostImpl* host) {
 
   host_ = host;
   UpdateTouchEventEmulationState();
-  ApplyDeviceEmulationState();
+  UpdateDeviceEmulationState();
 }
 
 void EmulationHandler::Detached() {
   touch_emulation_enabled_ = false;
   device_emulation_enabled_ = false;
   UpdateTouchEventEmulationState();
-  ApplyDeviceEmulationState();
+  UpdateDeviceEmulationState();
 }
 
 Response EmulationHandler::SetGeolocationOverride(
@@ -200,7 +192,7 @@ Response EmulationHandler::SetDeviceMetricsOverride(
 
   device_emulation_enabled_ = true;
   device_emulation_params_ = params;
-  DeviceEmulationNeedsUpdate();
+  UpdateDeviceEmulationState();
   return Response::OK();
 }
 
@@ -209,7 +201,7 @@ Response EmulationHandler::ClearDeviceMetricsOverride() {
     return Response::OK();
 
   device_emulation_enabled_ = false;
-  DeviceEmulationNeedsUpdate();
+  UpdateDeviceEmulationState();
   return Response::OK();
 }
 
@@ -233,31 +225,11 @@ void EmulationHandler::UpdateTouchEventEmulationState() {
     GetWebContents()->SetForceDisableOverscrollContent(enabled);
 }
 
-void EmulationHandler::DeviceEmulationNeedsUpdate() {
-  device_emulation_needs_update_ = true;
-  if (!device_emulation_waiting_for_frame_)
-    ApplyDeviceEmulationState();
-}
-
-void EmulationHandler::OnSwapCompositorFrame() {
-  frame_timer_->Stop();
-  device_emulation_waiting_for_frame_ = false;
-  if (device_emulation_needs_update_)
-    ApplyDeviceEmulationState();
-}
-
-void EmulationHandler::ApplyDeviceEmulationState() {
-  device_emulation_needs_update_ = false;
+void EmulationHandler::UpdateDeviceEmulationState() {
   RenderWidgetHostImpl* widget_host =
       host_ ? host_->GetRenderWidgetHost() : nullptr;
   if (!widget_host)
     return;
-  device_emulation_waiting_for_frame_ = true;
-  frame_timer_->Start(
-      FROM_HERE,
-      base::TimeDelta::FromMilliseconds(kFrameTimeoutMs),
-      base::Bind(&EmulationHandler::OnSwapCompositorFrame,
-                 base::Unretained(this)));
   if (device_emulation_enabled_) {
     widget_host->Send(new ViewMsg_EnableDeviceEmulation(
         widget_host->GetRoutingID(), device_emulation_params_));
diff --git a/content/browser/devtools/protocol/emulation_handler.h b/content/browser/devtools/protocol/emulation_handler.h
index 4f1e26f..c2a4bd3 100644
--- a/content/browser/devtools/protocol/emulation_handler.h
+++ b/content/browser/devtools/protocol/emulation_handler.h
@@ -5,7 +5,6 @@
 #ifndef CONTENT_BROWSER_DEVTOOLS_PROTOCOL_EMULATION_HANDLER_H_
 #define CONTENT_BROWSER_DEVTOOLS_PROTOCOL_EMULATION_HANDLER_H_
 
-#include "base/timer/timer.h"
 #include "content/browser/devtools/protocol/devtools_protocol_dispatcher.h"
 #include "content/browser/devtools/protocol/page_handler.h"
 #include "third_party/WebKit/public/web/WebDeviceEmulationParams.h"
@@ -33,7 +32,6 @@ class EmulationHandler : public page::PageHandler::ScreencastListener {
 
   void SetRenderFrameHost(RenderFrameHostImpl* host);
   void Detached();
-  void OnSwapCompositorFrame();
 
   Response SetGeolocationOverride(double* latitude,
                                   double* longitude,
@@ -61,18 +59,13 @@ class EmulationHandler : public page::PageHandler::ScreencastListener {
  private:
   WebContentsImpl* GetWebContents();
   void UpdateTouchEventEmulationState();
-
-  void DeviceEmulationNeedsUpdate();
-  void ApplyDeviceEmulationState();
+  void UpdateDeviceEmulationState();
 
   bool touch_emulation_enabled_;
   std::string touch_emulation_configuration_;
 
   bool device_emulation_enabled_;
   blink::WebDeviceEmulationParams device_emulation_params_;
-  bool device_emulation_needs_update_;
-  bool device_emulation_waiting_for_frame_;
-  scoped_ptr<base::Timer> frame_timer_;
 
   page::PageHandler* page_handler_;
   RenderFrameHostImpl* host_;
diff --git a/content/browser/devtools/render_frame_devtools_agent_host.cc b/content/browser/devtools/render_frame_devtools_agent_host.cc
index 4c5b369..fb191fb 100644
--- a/content/browser/devtools/render_frame_devtools_agent_host.cc
+++ b/content/browser/devtools/render_frame_devtools_agent_host.cc
@@ -716,8 +716,6 @@ void RenderFrameDevToolsAgentHost::OnSwapCompositorFrame(
     page_handler_->OnSwapCompositorFrame(base::get<1>(param).metadata);
   if (input_handler_)
     input_handler_->OnSwapCompositorFrame(base::get<1>(param).metadata);
-  if (emulation_handler_)
-    emulation_handler_->OnSwapCompositorFrame();
   if (frame_trace_recorder_ && tracing_handler_->did_initiate_recording()) {
     frame_trace_recorder_->OnSwapCompositorFrame(
         current_ ? current_->host() : nullptr,
@@ -731,8 +729,6 @@ void RenderFrameDevToolsAgentHost::SynchronousSwapCompositorFrame(
     page_handler_->OnSynchronousSwapCompositorFrame(frame_metadata);
   if (input_handler_)
     input_handler_->OnSwapCompositorFrame(frame_metadata);
-  if (emulation_handler_)
-    emulation_handler_->OnSwapCompositorFrame();
   if (frame_trace_recorder_ && tracing_handler_->did_initiate_recording()) {
     frame_trace_recorder_->OnSynchronousSwapCompositorFrame(
         current_ ? current_->host() : nullptr,