Create base::Feature for using video capture API in DevTools

Create a base::Feature for using video capture API in DevTools so we
can do finch trial independent of Viz.

Bug: 813929
Change-Id: I44da043f473d8be663931306e7e9dd296143b1c4
Reviewed-on: https://chromium-review.googlesource.com/963183Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Antoine Labour <piman@chromium.org>
Commit-Queue: Saman Sami <samans@chromium.org>
Cr-Commit-Position: refs/heads/master@{#543972}

chrome/browser/devtools/devtools_eye_dropper.cc

@@ -12,6 +12,7 @@
 #include "content/public/browser/render_widget_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/content_features.h"
 #include "content/public/common/cursor_info.h"
 #include "content/public/common/screen_info.h"
 #include "media/base/limits.h"
@@ -31,8 +32,10 @@ DevToolsEyeDropper::DevToolsEyeDropper(content::WebContents* web_contents,
       last_cursor_y_(-1),
       host_(nullptr),
       video_consumer_binding_(this),
-      enable_viz_(
-          base::FeatureList::IsEnabled(features::kVizDisplayCompositor)),
+      use_video_capture_api_(
+          base::FeatureList::IsEnabled(features::kVizDisplayCompositor) ||
+          base::FeatureList::IsEnabled(
+              features::kUseVideoCaptureApiForDevToolsSnapshots)),
       weak_factory_(this) {
   mouse_event_callback_ =
       base::Bind(&DevToolsEyeDropper::HandleMouseEvent, base::Unretained(this));
@@ -51,8 +54,7 @@ void DevToolsEyeDropper::AttachToHost(content::RenderWidgetHost* host) {
   host_ = host;
   host_->AddMouseEventCallback(mouse_event_callback_);
 
-  // TODO(crbug.com/813929): Use video capturer even if viz is not enabled.
-  if (!enable_viz_)
+  if (!use_video_capture_api_)
     return;
 
   // Capturing a full-page screenshot can be costly so we shouldn't do it too
@@ -118,7 +120,7 @@ void DevToolsEyeDropper::DidReceiveCompositorFrame() {
 }
 
 void DevToolsEyeDropper::UpdateFrame() {
-  if (enable_viz_ || !host_ || !host_->GetView())
+  if (use_video_capture_api_ || !host_ || !host_->GetView())
     return;
 
   // TODO(miu): This is the wrong size. It's the size of the view on-screen, and
@@ -139,7 +141,7 @@ void DevToolsEyeDropper::ResetFrame() {
 }
 
 void DevToolsEyeDropper::FrameUpdated(const SkBitmap& bitmap) {
-  DCHECK(!enable_viz_);
+  DCHECK(!use_video_capture_api_);
   if (bitmap.drawsNothing())
     return;
   frame_ = bitmap;

chrome/browser/devtools/devtools_eye_dropper.h

@@ -63,7 +63,7 @@ class DevToolsEyeDropper : public content::WebContentsObserver,
   content::RenderWidgetHost* host_;
   viz::mojom::FrameSinkVideoCapturerPtr video_capturer_;
   mojo::Binding<viz::mojom::FrameSinkVideoConsumer> video_consumer_binding_;
-  const bool enable_viz_;
+  const bool use_video_capture_api_;
   media::PaintCanvasVideoRenderer video_renderer_;
   base::WeakPtrFactory<DevToolsEyeDropper> weak_factory_;
 

content/browser/devtools/protocol/tracing_handler.cc

@@ -32,6 +32,7 @@
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/tracing/tracing_controller_impl.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/common/content_features.h"
 #include "services/resource_coordinator/public/cpp/memory_instrumentation/memory_instrumentation.h"
 #include "services/tracing/public/mojom/constants.mojom.h"
 
@@ -156,7 +157,9 @@ TracingHandler::TracingHandler(TracingHandler::Target target,
       return_as_stream_(false),
       gzip_compression_(false),
       weak_factory_(this) {
-  if (base::FeatureList::IsEnabled(features::kVizDisplayCompositor)) {
+  if (base::FeatureList::IsEnabled(features::kVizDisplayCompositor) ||
+      base::FeatureList::IsEnabled(
+          features::kUseVideoCaptureApiForDevToolsSnapshots)) {
     frame_trace_recorder_ =
         std::make_unique<DevToolsFrameTraceRecorderForViz>();
   }

content/browser/devtools/render_frame_devtools_agent_host.cc

@@ -12,6 +12,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "build/build_config.h"
+#include "components/viz/common/features.h"
 #include "content/browser/bad_message.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/devtools/devtools_frame_trace_recorder.h"
@@ -49,6 +50,7 @@
 #include "content/public/browser/render_widget_host_iterator.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "content/public/common/browser_side_navigation_policy.h"
+#include "content/public/common/content_features.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_request_headers.h"
@@ -397,7 +399,12 @@ bool RenderFrameDevToolsAgentHost::AttachSession(DevToolsSession* session) {
     session->AttachToAgent(agent_ptr_);
 
   if (sessions().size() == 1) {
-    frame_trace_recorder_.reset(new DevToolsFrameTraceRecorder());
+    // Taking screenshots using the video capture API is done in TracingHandler.
+    if (!base::FeatureList::IsEnabled(features::kVizDisplayCompositor) &&
+        !base::FeatureList::IsEnabled(
+            features::kUseVideoCaptureApiForDevToolsSnapshots)) {
+      frame_trace_recorder_.reset(new DevToolsFrameTraceRecorder());
+    }
     GrantPolicy();
 #if defined(OS_ANDROID)
     GetWakeLock()->RequestWakeLock();

content/public/common/content_features.cc

@@ -416,6 +416,14 @@ const base::Feature kUseMojoAudioOutputStreamFactory{
 const base::Feature kUserActivationV2{"UserActivationV2",
                                       base::FEATURE_DISABLED_BY_DEFAULT};
 
+// Use RenderWidgetHostView::CreateVideoCapturer instead of
+// RenderWidgetHostView::CopyFromSurface to obtain a stream of snapshots
+// captured from the renderer for DevTools performance timeline and eyedropper
+// tool.
+const base::Feature kUseVideoCaptureApiForDevToolsSnapshots{
+    "UseVideoCaptureApiForDevToolsSnapshots",
+    base::FEATURE_DISABLED_BY_DEFAULT};
+
 // Enables to use a snapshot file in creating V8 contexts.
 const base::Feature kV8ContextSnapshot{"V8ContextSnapshot",
                                        base::FEATURE_ENABLED_BY_DEFAULT};

content/public/common/content_features.h

@@ -100,6 +100,8 @@ CONTENT_EXPORT extern const base::Feature kUseFeaturePolicyForPermissions;
 CONTENT_EXPORT extern const base::Feature kUseMojoAudioInputStreamFactory;
 CONTENT_EXPORT extern const base::Feature kUseMojoAudioOutputStreamFactory;
 CONTENT_EXPORT extern const base::Feature kUserActivationV2;
+CONTENT_EXPORT extern const base::Feature
+    kUseVideoCaptureApiForDevToolsSnapshots;
 CONTENT_EXPORT extern const base::Feature kV8ContextSnapshot;
 CONTENT_EXPORT extern const base::Feature kV8VmFuture;
 CONTENT_EXPORT extern const base::Feature kVrWebInputEditing;