Use persistent ID/names for displays.

ui/gfx/display.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 "ui/gfx/display.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
 #include "base/stringprintf.h"
@@ skipping 14 matching lines @@
     std::string value = CommandLine::ForCurrentProcess()->
         GetSwitchValueASCII(switches::kForceDeviceScaleFactor);
     if (!base::StringToDouble(value, &scale_in_double))
       LOG(ERROR) << "Failed to parse the deafult device scale factor:" << value;
   }
   return static_cast<float>(scale_in_double);
 }
 
 } // namespace
 
+const int64 Display::kInvalidDisplayID = -1;
+
 // static
 float Display::GetForcedDeviceScaleFactor() {
   static const float kForcedDeviceScaleFactor =
       GetForcedDeviceScaleFactorImpl();
   return kForcedDeviceScaleFactor;
 }
 
+// static
+int64 Display::GetID(uint16 manufacturer_id, uint32 serial_number) {
+  int64 new_id = ((static_cast<int64>(manufacturer_id) << 32) | serial_number);
+  DCHECK_NE(kInvalidDisplayID, new_id);
+  return new_id;
+}
+
 Display::Display()
-    : id_(-1),
+    : id_(kInvalidDisplayID),
       device_scale_factor_(GetForcedDeviceScaleFactor()) {
 }
 
-Display::Display(int id)
+Display::Display(int64 id)
     : id_(id),
       device_scale_factor_(GetForcedDeviceScaleFactor()) {
 }
 
-Display::Display(int id, const gfx::Rect& bounds)
+Display::Display(int64 id, const gfx::Rect& bounds)
     : id_(id),
       bounds_(bounds),
       work_area_(bounds),
       device_scale_factor_(GetForcedDeviceScaleFactor()) {
 #if defined(USE_AURA)
   SetScaleAndBounds(device_scale_factor_, bounds);
 #endif
 }
 
 Display::~Display() {
@@ skipping 33 matching lines @@
 void Display::UpdateWorkAreaFromInsets(const gfx::Insets& insets) {
   work_area_ = bounds_;
   work_area_.Inset(insets);
 }
 
 gfx::Size Display::GetSizeInPixel() const {
   return size().Scale(device_scale_factor_);
 }
 
 std::string Display::ToString() const {
-  return base::StringPrintf("Display[%d] bounds=%s, workarea=%s, scale=%f",
-                            id_,
+  return base::StringPrintf("Display[%lld] bounds=%s, workarea=%s, scale=%f",
+                            static_cast<long long int>(id_),
                             bounds_.ToString().c_str(),
                             work_area_.ToString().c_str(),
                             device_scale_factor_);
 }
 
 }  // namespace gfx