Removed requirement for the renderer to know it's process ID

content/browser/renderer_host/render_widget_host_impl.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 
 #include <math.h>
 #include <set>
 #include <utility>
 
@@ skipping 1480 matching lines @@
                                                    ack_params);
     return;
   }
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params gpu_params;
   gpu_params.surface_id = params.surface_id;
   gpu_params.surface_handle = params.surface_handle;
   gpu_params.route_id = params.route_id;
   gpu_params.size = params.size;
   gpu_params.scale_factor = params.scale_factor;
   gpu_params.latency_info = params.latency_info;
+  FixMissingLatencyInfoComponentIds(gpu_params.latency_info);
   view_->AcceleratedSurfaceBuffersSwapped(gpu_params,
                                           params.gpu_process_host_id);
   view_->DidReceiveRendererFrame();
 }
 #endif  // OS_MACOSX
 
 bool RenderWidgetHostImpl::OnSwapCompositorFrame(
     const IPC::Message& message) {
   ViewHostMsg_SwapCompositorFrame::Param param;
   if (!ViewHostMsg_SwapCompositorFrame::Read(&message, &param))
     return false;
   scoped_ptr<cc::CompositorFrame> frame(new cc::CompositorFrame);
   uint32 output_surface_id = param.a;
   param.b.AssignTo(frame.get());
 
+  for (size_t i = 0; i < frame->metadata.latency_info.size(); i++)
+    FixMissingLatencyInfoComponentIds(frame->metadata.latency_info[i]);
+
   input_router_->OnViewUpdated(
       GetInputRouterViewFlagsFromCompositorFrameMetadata(frame->metadata));
 
   if (view_) {
     view_->OnSwapCompositorFrame(output_surface_id, frame.Pass());
     view_->DidReceiveRendererFrame();
   } else {
     cc::CompositorFrameAck ack;
     if (frame->gl_frame_data) {
       ack.gl_frame_data = frame->gl_frame_data.Pass();
@@ skipping 144 matching lines @@
       NotificationService::NoDetails());
 
   // We don't need to update the view if the view is hidden. We must do this
   // early return after the ACK is sent, however, or the renderer will not send
   // us more data.
   if (is_hidden_)
     return;
 
   // Now paint the view. Watch out: it might be destroyed already.
   if (view_ && !is_accelerated_compositing_active_) {
+
+    std::vector<ui::LatencyInfo> latency_info;
+    for (size_t i = 0; i < params.latency_info.size(); i++) {
+      ui::LatencyInfo info = params.latency_info[i];
+      FixMissingLatencyInfoComponentIds(info);
+      latency_info.push_back(info);
+    }
+
     view_being_painted_ = true;
     view_->DidUpdateBackingStore(params.scroll_rect, params.scroll_delta,
-                                 params.copy_rects, params.latency_info);
+                                 params.copy_rects, latency_info);
     view_->DidReceiveRendererFrame();
     view_being_painted_ = false;
   }
 
   // If we got a resize ack, then perhaps we have another resize to send?
   bool is_resize_ack =
       ViewHostMsg_UpdateRect_Flags::is_resize_ack(params.flags);
   if (is_resize_ack)
     WasResized();
 
@@ skipping 812 matching lines @@
           continue;
         }
         RenderWidgetHostImpl* rwhi = RenderWidgetHostImpl::From(rwh);
         if (rwhi_set.insert(rwhi).second)
           rwhi->FrameSwapped(latency_info[i]);
       }
     }
   }
 }
 
+void RenderWidgetHostImpl::FixMissingLatencyInfoComponentIds(
+    ui::LatencyInfo& latency_info) {
+  ui::LatencyInfo::LatencyMap::iterator lc =
+      latency_info.latency_components.begin();
+  while (lc != latency_info.latency_components.end()) {
+    ui::LatencyComponentType component_type = lc->first.first;
+    if (component_type == ui::WINDOW_SNAPSHOT_FRAME_NUMBER_COMPONENT) {
+      // If the component's ID is 0, patch it with the correct value.
+      if (lc->first.second == 0) {

[jam, 2014/01/17 01:27:27]

i think we should always set it if it's coming from the renderer. that way a
renderer can't put a non-zero value and then we'd trust it.

+        // Generate a new component entry
+        ui::LatencyInfo::LatencyMap::key_type key =
+            std::make_pair(component_type, GetLatencyComponentId());
+        latency_info.latency_components[key] = lc->second;
+
+        // Remove the old entry
+        latency_info.latency_components.erase(lc++);
+        continue;
+      }
+    }
+    ++lc;
+  }
+}
+
 }  // namespace content