Added Client-Hints.

chrome/browser/net/client_hints.cc

Index: chrome/browser/net/client_hints.cc
diff --git a/chrome/browser/net/client_hints.cc b/chrome/browser/net/client_hints.cc
new file mode 100644
index 0000000000000000000000000000000000000000..de6cd7c6a3a9af00b0e539b566b43d5519522752
--- /dev/null
+++ b/chrome/browser/net/client_hints.cc
@@ -0,0 +1,83 @@
+// 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 "chrome/browser/net/client_hints.h"
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/stringprintf.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/render_widget_host_view.h"
+#include "webkit/glue/webkit_glue.h"
+
+using content::BrowserThread;
+using content::RenderViewHost;
+using content::RenderWidgetHostViewPort;
+
+ClientHints::ClientHints() {
+}
+
+ClientHints::~ClientHints() {
+}
+
+bool ClientHints::RetrieveScreenInfoIfUnavailable(int process_id,
+                                                  int render_view_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+      base::Bind(&ClientHints::FetchScreenInfoOnUIThread, this,
+                 process_id, render_view_id));
+  return IsScreenInfoAvailable(process_id, render_view_id);
+}
+
+bool ClientHints::IsScreenInfoAvailable(int process_id, int render_view_id) {
+  ScreenMap::iterator it =
+      screen_hints_.find(std::pair<int, int>(process_id, render_view_id));
+  if (it == screen_hints_.end())
+    return false;
+
+  return true;
+}
+
+std::string ClientHints::GetScreenInfoHints(int process_id,
+                                            int render_view_id) {
+  ScreenMap::iterator it =
+      screen_hints_.find(std::pair<int, int>(process_id, render_view_id));
+  DCHECK(it != screen_hints_.end());
+  return (*it).second.hints_str;
+}
+
+void ClientHints::FetchScreenInfoOnUIThread(int process_id,
+                                            int render_view_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  RenderViewHost* render_view_host =
+      RenderViewHost::FromID(process_id, render_view_id);
+  if (render_view_host == NULL || render_view_host->GetView() == NULL)
+    return;
+  WebKit::WebScreenInfo screen_info;
+#if defined(OS_POSIX) || defined(USE_AURA)

[jam, 2013/01/17 18:14:35]

why are you doing this only for these too?

GetScreenInfo appears to be an internal detail of content, which is why it's in
content/port (and not content/public).

chrome layer is the one that manages teh browser size, why should it go to
content to ask something it should know itself?

[bengr (incorrect), 2013/01/18 02:12:00]

I now get the device pixel ratio more directly.

On 2013/01/17 18:14:35, John Abd-El-Malek wrote:

+  render_view_host->GetView()->GetScreenInfo(&screen_info);
+#else
+  screen_info.deviceScaleFactor = 0.0;

[igrigorik, 2013/02/09 17:06:30]

Is there a specific reason for 0.0? I think by default we should assume 1.0 -
aka, physical pixel count is the same as CSS pixel count.

+#endif
+  gfx::Rect rect = render_view_host->GetView()->GetViewBounds();
+  BrowserThread::PostTask(BrowserThread::IO, FROM_HERE,
+      base::Bind(&ClientHints::UpdateScreenInfo, this,
+                 process_id, render_view_id, rect.width(), rect.height(),
+                 screen_info.deviceScaleFactor));
+}
+
+void ClientHints::UpdateScreenInfo(int process_id, int render_view_id,
+                                   int width, int height,
+                                   float dpr) {
+  std::string screen_info_hints;
+  screen_info_hints = base::StringPrintf("vh=%d, vw=%d", height, width);
+#if defined(OS_POSIX) || defined(USE_AURA)
+  screen_info_hints += base::StringPrintf(", dpr=%0.3g", dpr);

[Ryan Sleevi, 2013/01/17 01:57:56]

StringAppendF(screen_info_hints, ", dpr=%0.3g", dpr);

[bengr (incorrect), 2013/01/18 02:12:00]

Done.

+#endif
+  screen_hints_[std::pair<int, int>(process_id, render_view_id)] =
+      ScreenHints(width, height, dpr, screen_info_hints);
+}
+
+