Adds scroll position/scale emulation to DevTools.

content/browser/devtools/protocol/emulation_handler.cc

Index: content/browser/devtools/protocol/emulation_handler.cc
diff --git a/content/browser/devtools/protocol/emulation_handler.cc b/content/browser/devtools/protocol/emulation_handler.cc
index 12c377a4fc84eab5396d2d195ded5158134a463f..da4a13da485e762f35e49a94c834f7124b5e73f0 100644
--- a/content/browser/devtools/protocol/emulation_handler.cc
+++ b/content/browser/devtools/protocol/emulation_handler.cc
@@ -146,7 +146,14 @@ Response EmulationHandler::SetDeviceMetricsOverride(
     const int* screen_height,
     const int* position_x,
     const int* position_y,
-    const std::unique_ptr<base::DictionaryValue>& screen_orientation) {
+    const std::unique_ptr<base::DictionaryValue>& screen_orientation,
+    const int* scroll_position_x,
+    const int* scroll_position_y,
+    const int* visual_viewport_width,
+    const int* visual_viewport_height,
+    const double* visual_viewport_position_x,
+    const double* visual_viewport_position_y,
+    const double* visual_viewport_scale) {
   const static int max_size = 10000000;
   const static double max_scale = 10;
   const static int max_orientation_angle = 360;
@@ -207,6 +214,44 @@ Response EmulationHandler::SetDeviceMetricsOverride(
     }
   }
 
+  if ((scroll_position_x &&
+       (*scroll_position_x < 0 || *scroll_position_x > max_size)) ||
+      (scroll_position_y &&
+       (*scroll_position_y < 0 || *scroll_position_y > max_size))) {
+    return Response::InvalidParams(
+        "Scroll position coordinates must be non-negative, not greater than " +
+        base::IntToString(max_size));
+  }
+
+  if ((visual_viewport_width &&
+       (*visual_viewport_width < 0 || *visual_viewport_width > max_size)) ||
+      (visual_viewport_height &&
+       (*visual_viewport_height < 0 || *visual_viewport_height > max_size))) {
+    return Response::InvalidParams(
+        "Visible_width and visible_height values must be positive, not greater "
+        "than " +
+        base::IntToString(max_size));
+  }
+
+  if ((visual_viewport_position_x &&
+       (*visual_viewport_position_x < 0 ||
+        *visual_viewport_position_x > max_size)) ||
+      (visual_viewport_position_y &&
+       (*visual_viewport_position_y < 0 ||
+        *visual_viewport_position_y > max_size))) {
+    return Response::InvalidParams(
+        "Visual viewport position coordinates must be non-negative, not "
+        "greater than " +
+        base::IntToString(max_size));
+  }
+
+  if (visual_viewport_scale &&
+      (*visual_viewport_scale <= 0 || *visual_viewport_scale > max_scale)) {
+    return Response::InvalidParams(
+        "Scale must be positive and not greater than " +
+        base::DoubleToString(max_scale));
+  }
+
   blink::WebDeviceEmulationParams params;
   params.screenPosition = mobile ? blink::WebDeviceEmulationParams::Mobile :
       blink::WebDeviceEmulationParams::Desktop;
@@ -223,6 +268,17 @@ Response EmulationHandler::SetDeviceMetricsOverride(
       optional_offset_y ? *optional_offset_y : 0.f);
   params.screenOrientationType = orientationType;
   params.screenOrientationAngle = orientationAngle;
+  params.scrollPosition =
+      blink::WebPoint(scroll_position_x ? *scroll_position_x : -1,
+                      scroll_position_y ? *scroll_position_y : -1);
+  params.visualViewportSize =
+      blink::WebSize(visual_viewport_width ? *visual_viewport_width : 0,
+                     visual_viewport_height ? *visual_viewport_height : 0);
+  params.visualViewportPosition = blink::WebFloatPoint(
+      visual_viewport_position_x ? *visual_viewport_position_x : -1,
+      visual_viewport_position_y ? *visual_viewport_position_y : -1);
+  params.visualViewportScale =
+      visual_viewport_scale ? *visual_viewport_scale : 0;
 
   if (device_emulation_enabled_ && params == device_emulation_params_)
     return Response::OK();
@@ -266,6 +322,7 @@ void EmulationHandler::UpdateDeviceEmulationState() {
       host_ ? host_->GetRenderWidgetHost() : nullptr;
   if (!widget_host)
     return;
+
   if (device_emulation_enabled_) {
     widget_host->Send(new ViewMsg_EnableDeviceEmulation(
         widget_host->GetRoutingID(), device_emulation_params_));