chromecast: Provide display information to display::Screen earlier

Chrome makes synchronous queries of screen geometry during startup. To
satisfy these requests, assume the the first call to configure the
primary display will succeed, and set this geometry in CastScreen
synchronously in the startup case.

DRM platform goes to great lengths to make this strategy work, by
querying display information synchronously in the browser process prior
to GPU process startup. It will also work for FakeDisplayDelegate. Cast
platform is not affected by this change.

BUG=b/74138444
TEST=chromecast browser tests

Change-Id: I68f88b78c151f938f99ed393fe630ecfa5b86dbc
Reviewed-on: https://chromium-review.googlesource.com/952099
Commit-Queue: Michael Spang <spang@chromium.org>
Reviewed-by: Sergey Volk <servolk@chromium.org>
Reviewed-by: Daniel Nicoara <dnicoara@chromium.org>
Cr-Commit-Position: refs/heads/master@{#541264}

chromecast/browser/cast_display_configurator.cc

@@ -81,7 +81,7 @@ CastDisplayConfigurator::CastDisplayConfigurator(CastScreen* screen)
   if (delegate_) {
     delegate_->AddObserver(this);
     delegate_->Initialize();
-    OnConfigurationChanged();
+    ForceInitialConfigure();
   } else {
     ConfigureDisplayFromCommandLine();
   }
@@ -95,9 +95,9 @@ CastDisplayConfigurator::~CastDisplayConfigurator() {
 // display::NativeDisplayObserver interface
 void CastDisplayConfigurator::OnConfigurationChanged() {
   DCHECK(delegate_);
-  delegate_->GetDisplays(
-      base::Bind(&CastDisplayConfigurator::OnDisplaysAcquired,
-                 weak_factory_.GetWeakPtr()));
+  delegate_->GetDisplays(base::Bind(
+      &CastDisplayConfigurator::OnDisplaysAcquired, weak_factory_.GetWeakPtr(),
+      false /* force_initial_configure */));
 }
 
 void CastDisplayConfigurator::ConfigureDisplayFromCommandLine() {
@@ -106,7 +106,14 @@ void CastDisplayConfigurator::ConfigureDisplayFromCommandLine() {
                GetRotationFromCommandLine());
 }
 
+void CastDisplayConfigurator::ForceInitialConfigure() {
+  delegate_->GetDisplays(base::Bind(
+      &CastDisplayConfigurator::OnDisplaysAcquired, weak_factory_.GetWeakPtr(),
+      true /* force_initial_configure */));
+}
+
 void CastDisplayConfigurator::OnDisplaysAcquired(
+    bool force_initial_configure,
     const std::vector<display::DisplaySnapshot*>& displays) {
   DCHECK(delegate_);
   if (displays.empty()) {
@@ -126,6 +133,17 @@ void CastDisplayConfigurator::OnDisplaysAcquired(
   }
 
   gfx::Point origin;
+  gfx::Size native_size(display->native_mode()->size());
+  if (force_initial_configure) {
+    // For initial configuration, pass the native geometry to gfx::Screen
+    // before calling Configure(), so that this information is available
+    // to chrome during startup. Otherwise we will not have a valid display
+    // during the first queries to display::Screen.
+    UpdateScreen(display->display_id(), gfx::Rect(origin, native_size),
+                 GetDeviceScaleFactor(native_size),
+                 GetRotationFromCommandLine());
+  }
+
   delegate_->Configure(
       *display, display->native_mode(), origin,
       base::BindRepeating(&CastDisplayConfigurator::OnDisplayConfigured,

chromecast/browser/cast_display_configurator.h

@@ -47,7 +47,9 @@ class CastDisplayConfigurator : public display::NativeDisplayObserver {
   void ConfigureDisplayFromCommandLine();
 
  private:
+  void ForceInitialConfigure();
   void OnDisplaysAcquired(
+      bool force_initial_configure,
       const std::vector<display::DisplaySnapshot*>& displays);
   void OnDisplayConfigured(display::DisplaySnapshot* display,
                            const display::DisplayMode* mode,