Compute pageScaleFactor on page so that fixed layout page fits width of window.

content/renderer/render_view_impl.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 "content/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/json/json_value_serializer.h"
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/process_util.h"
 #include "base/string_piece.h"
+#include "base/string_number_conversions.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "content/common/appcache/appcache_dispatcher.h"
 #include "content/common/clipboard_messages.h"
 #include "content/common/database_messages.h"
 #include "content/common/drag_messages.h"
 #include "content/common/file_system/file_system_dispatcher.h"
@@ skipping 487 matching lines @@
   renderer_accessibility_ = new RendererAccessibility(this);
   mouse_lock_dispatcher_ = new MouseLockDispatcher(this);
   intents_host_ = new WebIntentsHost(this);
 
   new IdleUserDetector(this);
 
   const CommandLine& command_line = *CommandLine::ForCurrentProcess();
   if (command_line.HasSwitch(switches::kDomAutomationController))
     enabled_bindings_ |= content::BINDINGS_POLICY_DOM_AUTOMATION;
 
+  bool enable_fixed_layout =
+      command_line.HasSwitch(switches::kEnableFixedLayout);
+  webview()->enableFixedLayoutMode(enable_fixed_layout);
+  if (enable_fixed_layout)
+      webview()->settings()->setFixedElementsLayoutRelativeToFrame(true);
+  base::StringToInt(command_line.GetSwitchValueASCII(
+                        switches::kDefaultDeviceScaleFactor),
+                    &default_device_scale_factor_);
+
   content::GetContentClient()->renderer()->RenderViewCreated(this);
 }
 
 RenderViewImpl::~RenderViewImpl() {
   history_page_ids_.clear();
 
   if (decrement_shared_popup_at_destruction_)
     shared_popup_counter_->data--;
 
   // If file chooser is still waiting for answer, dispatch empty answer.
@@ skipping 3820 matching lines @@
 
 void RenderViewImpl::OnMoveOrResizeStarted() {
   if (webview())
     webview()->hidePopups();
 }
 
 void RenderViewImpl::OnResize(const gfx::Size& new_size,
                               const gfx::Rect& resizer_rect,
                               bool is_fullscreen) {
   if (webview()) {
+    // This setting has no effect if fixed layout is not enabled.
+    if (default_device_scale_factor_)
+      webview()->settings()->setLayoutFallbackWidth(
+          new_size.width() / default_device_scale_factor_);
     webview()->hidePopups();
     if (send_preferred_size_changes_) {
       webview()->mainFrame()->setCanHaveScrollbars(
           ShouldDisplayScrollbars(new_size.width(), new_size.height()));
     }
     UpdateScrollState(webview()->mainFrame());
   }
 
   RenderWidget::OnResize(new_size, resizer_rect, is_fullscreen);
 }
@@ skipping 665 matching lines @@
 bool RenderViewImpl::WebWidgetHandlesCompositorScheduling() const {
   return !!RenderThreadImpl::current()->compositor_thread();
 }
 
 void RenderViewImpl::OnJavaBridgeInit() {
   DCHECK(!java_bridge_dispatcher_.get());
 #if defined(ENABLE_JAVA_BRIDGE)
   java_bridge_dispatcher_.reset(new JavaBridgeDispatcher(this));
 #endif
 }