Add --content-shell-host-window-size switch to control the window size for content_shell.

content/shell/browser/shell.cc

Index: content/shell/browser/shell.cc
diff --git a/content/shell/browser/shell.cc b/content/shell/browser/shell.cc
index c2967afd5997fd4e42fb3c52cb32a452b725aeac..efddc3e748f0c06d9367d4bd7ff20ceae8eb63b6 100644
--- a/content/shell/browser/shell.cc
+++ b/content/shell/browser/shell.cc
@@ -39,6 +39,26 @@ base::Callback<void(Shell*)> Shell::shell_created_callback_;
 
 bool Shell::quit_message_loop_ = true;
 
+namespace {
+gfx::Size ShellDefaultSize() {
+  static gfx::Size default_shell_size;
+  if (!default_shell_size.IsEmpty())
+    return default_shell_size;
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kContentShellHostWindowSize)) {
+    const std::string size_str = command_line->GetSwitchValueASCII(
+                  switches::kContentShellHostWindowSize);
+    int width, height;
+    CHECK_EQ(2, sscanf(size_str.c_str(), "%dx%d", &width, &height));
+    default_shell_size = gfx::Size(width, height);
+  } else {
+    default_shell_size = gfx::Size(
+      Shell::kDefaultTestWindowWidthDip, Shell::kDefaultTestWindowHeightDip);
+  }
+  return default_shell_size;
+}
+}  // namespace
+
 class Shell::DevToolsWebContentsObserver : public WebContentsObserver {
  public:
   DevToolsWebContentsObserver(Shell* shell, WebContents* web_contents)
@@ -141,14 +161,13 @@ Shell* Shell::FromRenderViewHost(RenderViewHost* rvh) {
 
 // static
 void Shell::Initialize() {
-  PlatformInitialize(
-      gfx::Size(kDefaultTestWindowWidthDip, kDefaultTestWindowHeightDip));
+  PlatformInitialize(ShellDefaultSize());
 }
 
 gfx::Size Shell::AdjustWindowSize(const gfx::Size& initial_size) {
   if (!initial_size.IsEmpty())
     return initial_size;
-  return gfx::Size(kDefaultTestWindowWidthDip, kDefaultTestWindowHeightDip);
+  return ShellDefaultSize();
 }
 
 Shell* Shell::CreateNewWindow(BrowserContext* browser_context,