Update the user agent to request the mobile version site.

When we requeste a tab's mobile version site, we overwrite the user
agent's OS to Android OS so that the site can use its mobile version
layout. In this CL, when overwriting the user agent
- Update the Android version from Android 4.0.3 to Android 9
- Add "Chrome tablet" into its OS string
- Change product name from "Chrome" to "Chrome Mobile"
to increase the likelihood of sites adopting the user agent and
displaying the mobile version sites.

Bug: 953577
Change-Id: Ib72bd7abb1fa05dbcf9861b1d4d7ff8552c1f01d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1637649
Commit-Queue: Xiaoqian Dai <xdai@chromium.org>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#665168}

chrome/browser/ui/ash/chrome_new_window_client.cc

@@ -175,16 +175,8 @@ class CustomTabSessionImpl : public arc::mojom::CustomTabSession {
     std::unique_ptr<content::WebContents> web_contents =
         content::WebContents::Create(create_params);
 
-    // Use the same version number as browser_commands.cc
-    // TODO(hashimoto): Get the actual Android version from the container.
-    constexpr char kOsOverrideForTabletSite[] = "Linux; Android 4.0.3";
     // Override the user agent to request mobile version web sites.
-    const std::string product =
-        version_info::GetProductNameAndVersionForUserAgent();
-    const std::string user_agent = content::BuildUserAgentFromOSAndProduct(
-        kOsOverrideForTabletSite, product);
-    web_contents->SetUserAgentOverride(user_agent,
-                                       false /* override_in_new_tabs */);
+    chrome::SetAndroidOsForTabletSite(web_contents.get());
 
     content::NavigationController::LoadURLParams load_url_params(url);
     load_url_params.source_site_instance = site_instance;

chrome/browser/ui/browser_commands.cc

@@ -134,7 +134,7 @@
 
 namespace {
 
-const char kOsOverrideForTabletSite[] = "Linux; Android 4.0.3";
+const char kOsOverrideForTabletSite[] = "Linux; Android 9; Chrome tablet";
 
 translate::TranslateBubbleUiEvent TranslateBubbleResultToUiEvent(
     ShowTranslateBubbleResult result) {
@@ -1243,16 +1243,24 @@ void ToggleRequestTabletSite(Browser* browser) {
   NavigationEntry* entry = controller.GetLastCommittedEntry();
   if (!entry)
     return;
-  if (entry->GetIsOverridingUserAgent()) {
+  if (entry->GetIsOverridingUserAgent())
     entry->SetIsOverridingUserAgent(false);
-  } else {
+  else
+    SetAndroidOsForTabletSite(current_tab);
+  controller.Reload(content::ReloadType::ORIGINAL_REQUEST_URL, true);
+}
+
+void SetAndroidOsForTabletSite(content::WebContents* current_tab) {
+  DCHECK(current_tab);
+  NavigationEntry* entry = current_tab->GetController().GetLastCommittedEntry();
+  if (entry) {
     entry->SetIsOverridingUserAgent(true);
-    std::string product = version_info::GetProductNameAndVersionForUserAgent();
+    std::string product =
+        version_info::GetProductNameAndVersionForUserAgent() + " Mobile";
     current_tab->SetUserAgentOverride(content::BuildUserAgentFromOSAndProduct(
                                           kOsOverrideForTabletSite, product),
                                       false);
   }
-  controller.Reload(content::ReloadType::ORIGINAL_REQUEST_URL, true);
 }
 
 void ToggleFullscreenMode(Browser* browser) {

chrome/browser/ui/browser_commands.h

@@ -159,6 +159,10 @@ void DistillCurrentPage(Browser* browser);
 bool CanRequestTabletSite(content::WebContents* current_tab);
 bool IsRequestingTabletSite(Browser* browser);
 void ToggleRequestTabletSite(Browser* browser);
+// Overwrite the user agent's OS with Android OS so that the web content is
+// using its mobile version layout. Note it won't take effect until the web
+// contents is reloaded.
+void SetAndroidOsForTabletSite(content::WebContents* current_tab);
 void ToggleFullscreenMode(Browser* browser);
 void ClearCache(Browser* browser);
 bool IsDebuggerAttachedToCurrentTab(Browser* browser);