DevTools window doesn't restore its minimal size if it's shrinked to zero.

chrome/browser/ui/views/frame/browser_view.cc

 // Copyright (c) 2011 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/ui/views/frame/browser_view.h"
 
 #if defined(TOOLKIT_USES_GTK)
 #include <gtk/gtk.h>
 #endif
 
@@ skipping 113 matching lines @@
 using views::ColumnSet;
 using views::GridLayout;
 
 // The height of the status bubble.
 static const int kStatusBubbleHeight = 20;
 // The name of a key to store on the window handle so that other code can
 // locate this object using just the handle.
 static const char* const kBrowserViewKey = "__BROWSER_VIEW__";
 // How frequently we check for hung plugin windows.
 static const int kDefaultHungPluginDetectFrequency = 2000;
+
+// Minimal height of devtools pane or content pane when devtools are docked
+// to the browser window.
+const int kMinDevToolsHeight = 50;
+const int kMinContentsHeight = 50;
+
 // How long do we wait before we consider a window hung (in ms).
 static const int kDefaultPluginMessageResponseTimeout = 30000;
 // The number of milliseconds between loading animation frames.
 static const int kLoadingAnimationFrameTimeMs = 30;
 // The amount of space we expect the window border to take up.
 static const int kWindowBorderWidth = 5;
 
 // How round the 'new tab' style bookmarks bar is.
 static const int kNewtabBarRoundness = 5;
 // ------------
@@ skipping 1997 matching lines @@
       // Install devtools focus tracker when dev tools window is shown for the
       // first time.
       devtools_focus_tracker_.reset(
           new views::ExternalFocusTracker(devtools_container_,
                                           GetFocusManager()));
     }
 
     // Restore split offset.
     int split_offset = browser_->profile()->GetPrefs()->
         GetInteger(prefs::kDevToolsSplitLocation);
-    if (split_offset == -1) {
-      // Initial load, set to default value.
-      split_offset = 2 * contents_split_->height() / 3;
-    }
+    if (split_offset == -1)
+      split_offset = contents_split_->height() * 2 / 3;
+
     // Make sure user can see both panes.
-    int min_split_size = contents_split_->height() / 10;
-    split_offset = std::min(contents_split_->height() - min_split_size,
-                            std::max(min_split_size, split_offset));
+    split_offset = std::min(contents_split_->height() - kMinDevToolsHeight,
+                            split_offset);
+    split_offset = std::max(kMinContentsHeight, split_offset);
+    if (split_offset < 0)
+      split_offset = contents_split_->height() * 2 / 3;
     contents_split_->set_divider_offset(split_offset);
 
     devtools_container_->SetVisible(true);
     contents_split_->InvalidateLayout();
     Layout();
   } else if (should_hide) {
     // Store split offset when hiding devtools window only.
     browser_->profile()->GetPrefs()->SetInteger(prefs::kDevToolsSplitLocation,
         contents_split_->divider_offset());
 
@@ skipping 435 matching lines @@
   view->GetWindow()->non_client_view()->SetAccessibleName(
       l10n_util::GetStringUTF16(IDS_PRODUCT_NAME));
   return view;
 }
 #endif
 
 // static
 FindBar* BrowserWindow::CreateFindBar(Browser* browser) {
   return browser::CreateFindBar(static_cast<BrowserView*>(browser->window()));
 }